• 


NEW  CENTURY 

INTERMEDIATE 

D 


A, 

4 
A 


DEP> 

Gift 


No. 


NEW   CENTUKY   SERIES 

OF 

ANATOMY  PHYSIOLOGY  AND  HYGIENE 

BY 
WINFIELD  S.  HALL,  PH.D.  M.D.  (LEIPSIC) 

Professor  of  Physiology, 
Northwestern  University  Medical  School,  Chicago. 

HENEY  F.  HEWES,  A.B.,  M.D.  (HARVARD) 

Instructor  in  Physiological  and  Clinical  Chemistry, 
Harvard  University  Medical  School,  Boston. 

JEANNETTE   WINTEE   HALL 

Special  Teacher  of  Physiology,  Berwyn,  Illinois. 

HENEIETTA  AMELIA  MIEICK,  A.B.  (WELLESLEY) 

Assistant  Editor  School  Physiology  Journal,  Boston. 


NEW   CENTURY   SERIES 
OF  ANATOMY   PHYSIOLOGY   AND   HYGIENE 


1.  ANATOMY  PHYSIOLOGY  AND  HYGIENE 

For  High  Schools 

By  HENRY  F.  HEWES,  A.BV  M.D.  (Harvard),  Instructor  in  Physiologi- 
cal and  Clinical  Chemistry,  Harvard  University  Medical  School, 
Boston. 

2.  ELEMENTARY  ANATOMY  PHYSIOLOGY  AND  HYGIENE 

For  Higher  Grammar  Grades 

,  By  WINFIELD  S.  HALL,  PH.D.,  M.D.  (Leipsic),  Professor  of  Physiology, 
Northwestern  University  Medical  School,  Chicago. 

3.  INTERMEDIATE  PHYSIOLOGY  AND  HYGIENE 

For  Fifth  and  Sixth  Year  Pupils,  or  Corresponding  Classes  in 

Ungraded  Schools 

By  WINFIELD  S.  HALL,  PH.D.,  M.D.  (Leipsic),  Professor  of  Physiology, 
Northwestern  University  Medical  School,  Chicago,  and 

JEANNETTE  WINTER  HALL,  Special  Teacher  of  Physiology,  Berwyn, 
Illinois. 

4.  THE  NEW  CENTURY  PRIMER  OF  HYGIENE 

First  Book  for  Pupils1  Use 

By  JEANNETTE  WINTER  HALL,  Special  Teacher  of  Physiology,  Berwyn, 
Illinois. 

5.  ORAL  LESSON  BOOK  IN  HYGIENE 

For  Primary  Teachers 

By  HENRIETTA  AMELIA  MIRICK,  A.B.  (Wellesley),  Assistant  Editor 
School  Physiology  Journal,  Boston. 


NEW  CENTURY  SERIES 
OF  ANATOMY  PHYSIOLOGY  AND  HYGlEtfll'.  '•  :  \   ; 


INTERMEDIATE 
PHYSIOLOGY  AND  HYGIENE 


FOB 


LOWER   GRAMMAR   GRADES 


BT 

WINFIELD   S.  HALL,  PH.D.,  M.D.  (LEIPSIC) 
Professor  of  Physiology,  Northwestern  University  Medical  School,  Chicago 

AND 

JEANNETTE   WINTER   HALL 
Special  Teacher  of  Physiology  in  Berwyn,  III. 


NEW  YORK  .I.CINCINNATI  .I.CHICAGO 
AMERICAN    BOOJt    COMPANY 


EDUCATION  OfiF*.         Q 
INDORSEMENT 


1  WE,  the  undersigned,  have  carefully  examined  the  school  text-book 
Brtfcitl«(Jt     "  ."\ 

INTERMEDIATE   PHYSIOLOGY   AND    HYGIENE, 

by  PROFESSOR  WINFIELD  S.   HALL,  M.D.,  and  JE ANNETTE  WINTER 
HALL,  with  reference  to  the  following  points  : 

1.  Fullness  and  accuracy  of  subject-matter  relating  to  the  nature 
and  effects  of  alcoholic  drinks  and  other  narcotics  upon  the  human 
system. 

2.  Amount  of  matter  on  general  hygiene. 

3.  Presentation  of  matter  with  regard  to  its  adaptability  to  the  class 
of  pupils  for  which  it  is  designed. 

We  are  satisfied  that  on  all  of  these  points,  as  well  as  in  the 
regular  anatomy  and  physiology,  the  treatment  is  as  complete  as  is 
required  for  a  book  of  this  grade,  and  fully  in  harmony  with  the 
results  of  the  latest  investigations.  We  therefore  heartily  indorse 
the  book  for  Lower  Grammar  Grades,  or  for  corresponding  classes  in 
ungraded  schools. 

A.   H.  PLUMB,  D.D.  MRS.  MARY  H.  HUNT, 

REV.  JOSEPH  COOK,  LL.D.  World's  and  National  Superin- 

DANIEL  DORCHESTER,  D.D.  tendent  of  Scientific  Temperance 

WILLIAM  A.  MOWRY,  Pn.D.          Instruction    of    the    Woman's 
L.  D.  MASON,  M.D.  Christian  Temperance  Union. 

T.  D.  CROTHERS,  M.D. 
CHAS.  H.  SHEPARD,  M.D. 
GEORGE  W.  WEBSTER,  M.D. 
Text-book  Committee  of  the  Ad- 
visory Board. 

COPYRIGHT,    1901,   BY 

AMERICAN  BOOK  COMPANY. 
ENTERED  AT  STATIONERS'  HALL,  LONDON. 


HALL    INTER.  PHY8. 
W.     P.     8 


PREFACE 

MAN  is  a  part  of  the  great  harmonious  and 
united  realm  of  nature.  The  study  of  the  human 
body  is  therefore  a  legitimate  part  of  the  nature 
study  of  the  schools. 

The  method  which  has  met  the  universal  ap- 
proval of  all  true  teachers  in  nature  study  is  for 
the  pupil  to  observe  directly  and  with  his  own 
senses  the  objects  to  be  studied.  In  harmony 
with  this  fundamental  principle  of  pedagogy  the 
authors  of  this  book  have  endeavored  to  use  every 
opportunity  to  make  the  human  body  the  object 
of  direct  study  by  the  pupil.  Through  this  method 
the  pupil  becomes  interested  in  his  body  and  its 
care. 

Especial  attention  is  called  to  the  various  com- 
parisons between  the  human  body  and  the  bodies 
of  the  lower  animals.  The  object  of  this  com- 
parative study  is  to  impress  upon  the  mind  of  the 
pupil  the  unity  of  nature,  and  to  cultivate  in  him 
a  love  and  sympathy  for  the  lower  animals. 

54!?83 


6  PREFACE 

When  physiology  is  seen  to  be  an  integral  part 
of  nature  study  work  and  of  the  biology  of  our 
educational  system,  it  will  not  fail  to  be  one  of  the 
most  interesting  studies  of  the  whole  curriculum. 


CHICAGO,  ILL. 


WINFIELD   S.  HALL. 
JEAN^ETTE   W.  HALL. 


CONTENTS 

•MB 

The  Needs  of  a  Town 9 

Why  we  eat 14 

What  we  eat :  Foods 16 

Where  does  the  Food  come  from? 21 

How  to  prepare  Food 26 

Table  Manners 28 

What  we  drink 33 

What  the  Mouth  does  to  help  in  Digestion      ....  40 

How  the  Food  is  swallowed 43 

How  the  Food  is  digested 44 

How  the  Food  is  taken  up  from  the  Intestine          ...  46 

How  to  take  Care  of  the  Stomach 46 

How  the  Food  is  taken  up  by  the  Body 49 

How  the  Food  is  used  by  the  Body 53 

Some  Things  that  harm  the  Body 55 

The  Blood 63 

The  Heart  Beat  and  the  Pulse 71 

How  the  Blood  is  made  Pure 74 

The  Organs  with  which  we  breathe 75 

The  Waste  Matter  of  the  Body,  and  how  it  is  thrown  off       .  .  84 

The  Skin  and  its  Work 86 

The  Hair  and  the  Nails 90 

Bathing 93 

Cleanliness  and  Health 97 

7 


8  CONTENTS 

PAGE 

How  the  Body  is  warmed 99 

Seeing 103 

Hearing 109 

Smell 115 

Taste 117 

Touch 120 

How  we  think  and  what  we  think  with 125 

Education 129 

Sleep 133 

Some  Enemies  of  the  Body 136 

What  Doctors  and  Teachers  say  about  the  Use  of  Tobacco    .  141 

The  Body  Framework 144 

The  Skeleton 147 

Effect  of  Alcohol  and  Tobacco  upon  the  Bones       .         .        .151 

The  Framework  of  Other  'Animals 152 

How  the  Body  moves 156 

The  Care  of  the  Muscles 159 

Exercise 163 

How  Tobacco  effects  Muscular  Exercise  and  Growth      .         .  166 

Clothing 173 

How  Lack  of  Cleanliness  leads  to  Disease        .        .        .  176 


PHYSIOLOGY 


THE  NEEDS   OF  A  TOWN 

IF  you  were  to  go  some  summer  day  to  a 
certain  mountain  town  in  Pennsylvania,  and, 
climbing  one  of  the  hills  close 
by  the  town,  were  to  sit  down 
and  look  about  you,  you  would 
see  how  much  work  and  thought 
and  planning  it  takes  to  care 
for  the  people  of  one  little 
town. 

Away  off  to  the  east  beyond 
the  town  are  the  fields  of  ripe 
grain  which  the  farmers  are  busy 
cutting;  on  the  road  which 
winds  down  into  the  town  are 
many,  many  teams  bringing  the 
grain  to  the  mill.  The  mill  is 
that  tall  building  from  which 
you  see  the  wagons  carrying  the  loads  of  flour. 

Far  off  to  the  north  are  the  busy  coal  mines. 


10  PHYSIOLOGY 


You  oariTiat:  look  into  them  from  your  place  on 
,t,he,  bill,  but  you  can  see  the  cars  loaded  with  coal 
'doming  into  the  town,  and  the  boats,  too,  on  the 
canal,  bringing  coal  to  run  the  machinery  of  the 
factories,  and  to  furnish  fuel  for  the  houses. 


IN  A  COAL  MINE. 

On  the  hill  to  the  left  is  the  great  steam  pump 
that  sends  water  to  every  part  of  the  town.  Per- 
haps you  can  see  the  first  very  large  pipe,  but  the 
others  are  underground /and  out  of  sight.  -  From 
this  large  pipe  the  water  flows  into  smaller  pipes, 
and  these  branch  off  into  still  smaller  ones  until 


THE   NEEDS  OF  A  TOWN  11 

at  last  they  enter  the  houses  through  the  smallest 
pipes.  There  the  water  is  used  and  is  sent  out 
again  in  little  pipes  which  empty  into  larger  ones 
and  still  larger  ones  until  it  is  carried  off  by  the 
largest  pipe,  or  main  sewer. 

See  the  policemen  and  the  watchmen  walking 
back  and  forth,  guarding  the  people  and  all  that 
belongs  to  them,  to  keep  all 
safe  from  harm  !     Do  you  see 
that  large  building  near  the 
center  of  the  town?      That 
is  the  central  telephone  sta- 
tion.    See  how  many  wires 
pass  out  from  this  building 
and  go  out  in  every  direction  • 

all  over  the  town. 

If  you  could  only  listen  a  little  while  to  what 
is  being  said  over  those  wires,  you  would  hear  the 
miller  asking  the  farmer  about  the  grain,  and 
the  baker  asking  the  miller  to  send  the  flour,  and 
the  women  in  the  houses  asking  to  have  the  bread 
sent  to  them.  You  would  hear  the  policemen 
sending  word  about  danger  at  the  bridge  or  at  the 
mines ;  you  would  hear  people  asking  for  more 
coal  and  for  different  kinds  of  food.  You  would 


12 


PHYSIOLOGY 


hear  still  others  directing  where  the  coal  shall  be 
taken  and  what  shall  be  done  with  the  grain  and 
other  foods. 


THE   NEEDS   OF   A   TOWN  (continued) 

IF  you  watch  all  this  life  and  motion,  and  see 
what  it  all  means,  you   will  surely  say :  "  How 


many  things  it  takes  to  look  after  all  the  needs 
of  a  town!"  —  the  miner  and  the  farmer  to  pro- 
vide fuel  to  keep  the  people  warm  and  grow  food 


THE   NEEDS  OF  A   TOWN  13 

for  their  bodies;  the  miller  to  grind  the  grain 
into  flour ;  the  baker  to  put  the  food  into  form  to 
be  used ;  the  many  wagons,  cars,  and  boats  to  carry 
the  fuel  and  food  from  the  place  where  they  are 
prepared  to  the  place  where  they  are  used ;  the 
pump  and  one  set  of  pipes  to  send  the  water 
wherever  it  is  needed,  and  another  set  of  pipes 
to  carry  away  the  waste ;  the  guards  to  keep  the 
people  safe  ;  the  telephone  system  which  lets  each 
worker  know  what  the  other  workers  are  doing 
and  keeps  all  things  working  together. 

If  you  are  surprised  to  see  how  much  is  needed 
to  supply  a  town  full  of  people,  you  will  be 
more  surprised  to  know  that  each  person  has  within 
himself  needs  similar  to  all  of  those  that  we 
have  found  in  a  town.  Each  person  has  within 
himself  means  for  satisfying  all  of  these  needs. 

As  we  study  the  body  we  shall  find  it  very 
much  like  a  town,  and  that  it  has  what  corre- 
sponds to  a  mill,  a  place  to  prepare  food ;  what 
corresponds  to  wagons  and  carts,  in  which  food 
and  fuel  are  carried  about ;  pipes  in  which  liquid 
is  carried  over  the  body ;  and  other  pipes  in  which 
the  waste  is  taken  up  and  either  made  clean  and 
used  over  again  or  carried  away.  It  has  what 


14  PHYSIOLOGY 

corresponds  to  a  telephone  system,  by  which  each 
part  of  the  body  knows  what  the  other  parts 
are  doing,  and  even  policemen  and  watchmen  to 
warn  of  danger  and  to  keep  everything  safe. 


WHY    WE   EAT 

HAVE  you  ever  thought  how  much  time  is 
spent  in  growing,  preparing,  selling,  buying, 
cooking,  serving,  and  eating  food  ?  I  have  even 
known  little  girls  who  had  to  wash  dishes,  and 
boys  who  had  to  bring  in  fuel  for  the  cooking, 
to  wish  that  we  did  not  have  to  eat ;  but  they 
never  seem  to  wish  that  just  before  dinner.  Let 
us  see  why  we  spend  so  much  time  in  this  way. 

If  the  legs  or  arms  of  the  chairs  had  to  be 
made  longer,  the  carpenter  would  have  to  add 
a  piece  of  wood  to  each.  When  a  child's  arms 
and  legs  become  longer  and  longer  each  year, 
we  know  that  something  must  have  been  added. 
That  something  was  the  food  which  the  child 
ate,  and  unless  some  food  is  added  there  could 
be  no  growing.  Even  if  we  are  not  growing, 
we  still  need  some  food. 

If   boys    or    girls    climb    trees  or    fences,   their 


WHY   WE   EAT 


15 


clothes    usually  need    mending,    and   new  thread 
must  be  woven  in  and  out  or  new  cloth  must  be 


put  on.  Now,  the  body  that  does  the  climbing 
wears  out,  too,  and  must  be  mended,  not  with  cloth 
or  with  thread,  but  with  food.  There  is  no  other 


16  PHYSIOLOGY 

way  to  mend  the  body  which  wears  out  a  little 
with  every  motion  we  make,  with  every  thought 
we  have,  and  even  with  our  breathing. 

Your  mother  and  father,  who  are  now  more  than 
five  feet  tall,  were  once  smaller  than  you  are  now, 
and  it  is  the  food  which  they  have  eaten  which 
has  made  them  so  much  larger  than  they  were. 

Put  your  hand  on  the  window  glass  and  see 
how  cold  it  feels.  That  is  because  your  hand 
is  warmer  than  the  glass.  If  there  is  no  fire  in 
the  house  it  feels  cold,  and  so  would  your  body 
feel  cold  if  there  were  nothing  within  to  keep  it 
warm.  To  keep  the  body  warm  is  another  part 
of  the  work  which  the  food  does.  Now  we  see 
why  so  much  of  our  time  must  be  given  to 
getting,  preparing,  and  eating  food,  without  which 
we  could  not  keep  warm,  could  not  grow,  could 
not  even  live. 

We  eat  to  grow,  to  repair  our  bodies?  and  to  keep 
them  ivarm. 

WHAT  WE  EAT:    FOODS 

As  there  are  many  kinds  of  food  and  some 
are  much  better  than  others,  we  ought  to  know 


WHAT  WE   EAT:   FOODS  17 

something  of   the  different  kinds  and  what  they 
are  best  for. 

NATURE'S  FOOD  :   MILK  AND  EGGS 

Nature  has  given  us   two   foods   that   contain 
almost  everything  that  we  need  for  repairing  the 


,  MELKING  TIME. 

body,  for  growth  and  for  heat.  These  are  milk 
and  eggs,  which  may  be  taken  often  by  children, 
yes,  and  by  grown  people  as  well.  The  eggs  do 
much  more  good  when  they  are  boiled  soft,  or 
when  cooked  with  milk  in  custards  or  omelets, 
for  when  boiled  hard,  or  fried,  the  stomach  has 
hard  work  to  digest  them. 

HALL'S  INT.  PHYS. — 2 


18 


PHYSIOLOGY 


CEREAL  FOODS 

The  grain  which  the  farmer  grows  is  made  into 
white  flour,  graham  flour,  or  whole  wheat  flour,  or 
into  oatmeal,  or  corn  meal,  and  cereal  breakfast 
foods  of  all  kinds,  and  also  cereal  coffee.  All 


GRINDING  CEREALS. 

of  these  grain  foods,  excepting  white  flour,  are 
good  to  make  bones  and  teeth,  and  all  of  them 
give  heat  to  the  body;  if  too  much  cereal  food 
is  eaten  the  body  lays  on  fat.  If  you  want  your 
teeth  to  be  hard  and  firm  and  your  bones  to  be 
strong  and  hard,  do  not  say  you  will  not  eat 


WHAT   WE   EAT:    FOODS  19 

cereal  foods  and  graham  or  whole  wheat  bread, 
for  they,  with  milk,  give  the  lime  which  keeps 
the  bones  and  teeth  from  being  soft  and  weak. 

Hot  bread  and  biscuit,  when  made  of  white 
flour,  are  not  easy  for  the  stomach  to  digest. 
Breakfast  muffins  and  cakes,  when  made  of  whole 
wheat  flour,  of  graham  flour,  or  of  corn  meal,  are 
not  hard  for  the  stomach  to  digest,  and  may  be 
eaten  safely. 

MEAT 

Meat,  especially  lean  meat,  makes  muscle. 
Only  a  little  meat  is  needed  by  children;  too 
much  makes  them  restless  and  fretful.  Almost 
the  same  good  can  be  got  from  peas  and  beans 
as  from  meat,  while  they  are  much  cheaper  and 
do  not  have  the  bad  effect  which  comes  from  eat- 
ing jiiuch  meat. 

VEGETABLES    AND    FRUIT 

Many  vegetables  contain  starch  and  sugar  and 
other  nourishment  that  gives  us  strength,  heat, 
and  makes  the  body  grow ;  but  they  also  have 
mineral  matter  that  is  likewise  very  important. 
It  is  well  for  children  to  eat  many  different  kinds 
of  vegetables  in  order  to  get  the  minerals  which 


20 


PHYSIOLOGY 


POTATOES. 


they  contain.  Nearly  all  children  like  sugar  and 
sweet  things,  and  if  eaten  in  small  quantities  and 
at  the  right  time,  these  give  heat  and  strength 

to  the  body. 

There  is  a  good  deal 
of  sugar,  usually,  in  the 
food  which  is  prepared 
for  us  to  eat,  and  that 
is  why  we  cannot  eat 
much  more  without  hurting  our  stomachs.  A 
little  pure  candy  taken  at  the  end  of  the  dinner 
as  a  dessert  is  pleasing  to  the  taste  and  does  no 
harm  to  a  well  person,  and  in  cold  weather  a  little 
extra  sugar  helps  to 
keep  us  warm. 

Of  course  you  all  like 
fruit,  and  it  is  well  if 
you  can  have  plenty  of 
it ;  for  ripe,  fresh  fruit 
makes  one  feel  hungry 
for  other  foods,  and  in  the  summer  it  helps  to 
keep  one  cool  and  well. 

Sugar,  starch,  and  fat  help  to  make  us  warm, 
while  fruit  helps  to  keep  us  cool.  You  will  see 
from  this  that  we  should  eat  more  sugar,  starch, 


CABBAGES. 


WHERE  DOES  THE  FOOD  COME  FROM?          21 

and  fat  in  the  winter,  and  in  the  summer  let 
their  place  be  taken  in  part  by  cooling  fruits. 

With  fresh  fruit  and  light  puddings  for  dessert, 
and  occasionally  some  home- 
made candy,  you  will  surely 
be  willing  to  do  without  rich 
pies,  puddings,  #nd  cakes, 
which  do  you  no  good  and 
are  likely  to  do  you  real 

A  MELON. 

harm.      There    are    a    few 

other  things  which  children  are  much  better  with- 
out ;  they  are  spices,  mustard,  pepper,  catsup,  and 
strong  meat  sauces. 


WHERE  DOES  THE  FOOD  COME  FROM? 

IF  we,  ourselves,  were  obliged  to  go  and  gather 
all  we  eat,  we  should  take  some  very  long  journeys 
and  see  some  wonderful  sights. 

Suppose  for  dinner  we  are  to  have  whole 
wheat  bread  with  butter,  salmon,  roast  beef, 
potatoes,  spinach,  rice  pudding,  and  oranges. 
That  will  be  a  good  dinner,  but  I  fear  we  should 
be  very  hungry  before  we  had  anything  to  eat  if 
we  had  to  gather  together  all  the  raw  materials. 


22 


PHYSIOLOGY 


The  wheat  for  our  bread  may  be  grown  near 
home,  or  if  we  live  in  some  places  it  may  be 
that  we  must  journey  far  away  before  we  get 
the  wheat.  What  are  the  wheat  growing  states 
or  countries  ?  If  we  live  on  a  farm  we  can-  make 
our  own  butter,  but  many  of  us  do  not.  We  may 


REAPING  WHEAT. 


live  where  we  do  not  even  see   the   cow  which 

» 

gives  the  milk  from  which  the  butter  is  made. 
Perhaps  you  can  tell  the  best  places  for  cattle 
raising  and  butter  making.  We  might  use  canned 
salmon,  which  we  could  get  close  at  hand,  but 
as  we  have  started  to  get  our  dinner  from 
the  place  where  it  grows,  we  must  prepare  to 
take  a  ride  on  the  cars,  and  a  long  one,  too, 


WHERE  DOES  THE  FOOD  COME  FROM?         23 


unless  we  are  fortunate  enough  to  live  beside  one 
of  those  beautiful  rivers  where  the  salmon  lives. 
Do  you  know  where  the  home  of  the  salmon  is  ? 


SEINING  SALMON. 

We  always  think  of  beef  as  being  fresh,  and 
therefore  growing  just  where  we  live,   but  as  I 
sit  at  my  window  I  can  see, 
some    distance    away,   train 
after  train  coming  from  the  \i/&T 

West  loaded  with  cattle, 
sheep,  and  hogs.  Where  do 
they  come  from  ?  Where  are 
they  going  ?  Where  are  the 
great  cattle-raising  parts  of 
the  world? 

Some  of  you  can  get  pota- 
toes  right   OUt    of   your    Own         CUTTING  SUGAR  CANK. 


24 


PHYSIOLOGY 


garden  in  summer  time.  But  where  do  the  other 
potatoes  come  from,  and  where  do  we  get  spinach 
in  winter  time?  For  our  rice  pudding  we  must 
take  a  trip  to  the  South  to  get  rice  and  sugar,  and 


SALT  WORKS. 


while  we  are  there  we  might  get  the  oranges. 
Some  of  us,  perhaps,  live  nearer  to  another  place 
where  oranges  grow.  Where  do  oranges  and 
lemons  grow  the  best? 

The  milk  and  eggs  we  might  get  near  at  home, 


WHERE   DOES   THE   FOOD   COME   FROM? 


25 


but  we  have  not  yet  got  any  salt,  and  the  meal 
would  be  a  very  poor  one  without  that.  Who 
can  tell  where  we  would  better  go  to  get  good 
table  salt,  and  what  would  be  the  best  route  to 
take  ?  Would  it  not  be  a  good  plan  when  getting 


SHEEP. 


these  products  from  other  places  to  take  something 
with  us  from  home  to  exchange  for  them  ?  What 
shall  we  take  on  each  trip  ? 

Where  do  we  get  bananas  ?  pineapples  ?  cocoa- 
nuts  ?  chestnuts  ?  raisins  ?  dates  ?  figs  ?  prunes  ? 

Where  do  we  get  tea  ?  coffee  ?  cloves  ?  cinnamon  ? 
nutmegs  ?  pepper  ?  ginger  ?  and  mustard  ? 


26  PHYSIOLOGY 

Where  do  we  get  apricots?  quinces?  black- 
berries ?  blueberries  ?  cranberries  ?  and  peaches  ? 

Where  do  we  get  veal  ?  mutton  ?  rabbit  ?  grouse  ? 
quail?  and  venison? 


HOW  TO  PREPARE  FOOD 

APTEK  the  farmer  has  done  his  best  to  raise 
good  grain  and  good  meat  and  good  flour,  and 
the  butcher  has  prepared  the  meat  in  the  very 
best  way ;  and  after  we  have  chosen  those  things 
which  are  for  our  best  growth  in  every  way, 
there  is  still  a  very  important  part  to  be  done, 
and,  if  it  is  not  well  done,  it  will  undo  much  of 
the  good  of  the  work  done  before.  Unless  our 
food  is  well  cooked,  it  may  not  only  do  us  little 
good,  but  may  do  us  much  harm ;  we  ought  surely, 
then,  to  know  how  to  cook  what  we  eat. 

A  very  easy  way  to  cook  steak  or  chops  is  to 
fry  them,  but  there  is  another  way  as  easy  and 
much  better.  We  can  broil  them  by  holding  them 
over  the  coals  or  the  flame,  and  besides  giving 
them  a  much  more  delicious  taste  make  them 
very  easy  to  digest.  When  meat  is  roasted,  it 
must  have  a  very  hot  oven  at  first  that  the 


HOW  TO  PREPARE  FOOD  27 

outside  may  quickly  brown  over  and  keep  the 
juice  of  the  meat  from  running  out ;  but  it 
should  not  cook  too  long,  for  the  less  broiled 
and  roasted  meat  is  cooked,  the  easier  it  is  to 
digest.  When  meat  is  to  be  boiled,  it  must  be 
plunged  into  boiling  water  for  the  same  reason 
that  the  oven  must  be  hot  for  the  roast  meat, 
but  it  must  then  be  allowed  to  cook  for  a  long 
time,  and  very  slowly,  or  the  meat  will  become 
hard. 

A  cheap  cut  of  meat  may  be  made  to  give 
much  more  food  than  the  same  amount  of 
money  put  into  a  costly  cut,  if  it  is  cooked  slowly 
and  long  enough  to  soften  the  gristle  and  tough 
parts  and  to  cook  the  jelly  out  of  the  bones. 
Pork  is  not  so  healthful  as  other  meats.  When 
used,  it  should  be  cooked  very  thoroughly  to  kill 
the  little  germs  that  sometimes  live  in  lean  pork. 

Butter  is  a  healthful  and  nourishing  food,  and 
may  be  used  plentifully.  But  it  becomes  hard 
to  digest  when  heated,  and  that  is  why  anything 
fried  in  butter,  or  indeed  in  lard  or  other  fat, 
should  not  often  be  eaten. 

Any  vegetable  or  grain  that  contains  starch 
should  be  cooked  a  long  time,  for  raw  starch 


28  PHYSIOLOGY 

takes  more  than  twice  as  long  to  digest  as  cooked 
starch,  and  when  we  do  not  cook  it  long  enough 
we  make  the  stomach  do  more  work  than  it 
ought  to  do.  Many  cereal  breakfast  foods  con- 
tain starch,  and  need  to  be  cooked  a  long  time. 

Most  children  like  pancakes,  and  if  they  are 
made  of  corn  meal  or  graham  flour  or  some  other 
coarse  material,  and  are  baked  on  a  soapstone 
griddle  without  fat,  they  are  both  good  and 
healthful. 

These  few  things  have  been  said  just  to  show 
that  cooking  may  be  made  a  study  just  like  any 
other  science,  and  that  we  cannot  be  so  well  or 
so  able  to  do  good  work  on  food  that  has  been 
prepared  without  any  thought,  as  we  can  with 
thoughtfully  and  skillfully  prepared  food. 

TABLE   MANNERS 

WE  have  considered  the  various  kinds  of  food 
and  the  best  ways  of  cooking  it,  but  there  are 
still  other  important  matters  to  think  about  before 
we  are  ready  to  eat. 

Shall  we  tumble  the  food  on  the  table  in  any 
disorderly  way,  and  let  every  one  help  himself 
as  he  pleases  and  eat  in  noise  and  confusion  ? 


TABLE   MANNERS 


29 


The  best-cooked  dinner  in  the  world  would  lose 
much  of  its  good  effects  if  served  and  eaten  in 
such  a  fashion. 

To  get  the  most   good  from  a  meal,  we  must 


eat  it  in  an  orderly  way  and  in  pleasant  sur- 
roundings. For  this  reason  we  make  the  table 
look  as  pretty  as  possible.  We  have  the  cloth 
white  and  clean,  because  a  soiled  cloth  is  un- 
pleasant to  see.  We  have  the  prettiest  dishes 
we  can  afford,  and  we  put  them  upon  the  table 


30  PHYSIOLOGY 

in  the  best  possible  order.  We  put  flowers  upon 
the  table  if  we  can  have  them.  We  make  the 
food  look  as  tempting  as  possible  when  it  is 
brought  to  the  table  by  arranging  it  tastefully 
on  pretty  dishes  and  sometimes  garnishing  the 
meat  platter  with  sprigs  of  savory  greens,  such 
as  parsley  or  water  cress. 

But  a  well-set  table  is  not  all.  Those  who 
are  to  sit  around  it  must  look  their  best.  There 
must  be  no  soiled  hands  nor  faces,  unkempt  hair, 
nor  untidy  clothes. 

And  now  the  most  important  thing  of  all,  — 
there  must  be  no  frowning  faces,  sour  tempers, 
nor  cross  words.  A  wise  man  once  said, "  Better 
is  a  dinner  of  herbs  where  love  is  than  a  stalled 
ox  and  hatred  therewith."  To  say  disagreeable 
things  which  hurt  people's  feelings  is  wrong  at 
any  time,  but  to  say  them  at  table  is  doubly 
wrong,  for  an  unhappy  state  of  mind  interferes 
with  the  work  of  the  stomach. 

Never  tell  unpleasant  news  at  the  table,  nor 
talk  about  sickness,  death,  or  terrible  accidents. 
It  is  ,an  excellent  plan  to  save  up  the  good, 
funny  stories  you  hear  and  the  most  interesting 
things  you  read  about  to  relate  at  the  table. 


TABLE  MANNERS  31 

Compliments  and  pleasant  jokes  are  good  table- 
talk,  but  never  unkind  raillery  which  you  would 
not  like  to  have  turned  against  yourself. 

Then  there  are  certain  rules  about  eating  that 
one  should  learn  while  young  and  practice  until 
they  have  become  habits.  A  few  of  these 
are:  — 

Never  carry  food  to  your  mouth  with  a  knife. 

Never  make  noises  with  your  mouth  while  sip- 
ping your  drink  or  eating  your  food. 

Never  put  your  fingers  in  your  mouth. 

Always  wait  to  be  helped. 

Never  eat  fast. 

Learn  to  handle  your  knife,  fork,  spoon,  and 
napkin  in  the  proper  way. 

There  are  other  rules  that  every  one  needs  to 
know.  Perhaps  your  teacher  will  tell  you  these, 
and  perhaps  she  will  let  you  have  a  make-believe 
dinner  party  in  the  school  room  or  on  the  school 
grounds  some  day  where  the  girls  can  learn  how 
to  set  the  table,  and  both  boys  and  girls  can 
practice  all  the  rules  for  table  manners. 

One  of  the  most  important  rules  for  the  table 
as  well  as  elsewhere  is :  Always  be  kind  and 
thoughtful  of  the  welfare  of  others.  This  will 


32  PHYSIOLOGY 

keep  us  from  one  of  the  rudest  of  all  acts,  which 
is  to  laugh  at  other  people's  mistakes. 

A  story  told  of  a  certain  king  shows  clearly  the 
real  spirit  which  underlies  all  table  manners. 

At  supper  at  the  royal  table  were  once  two 
ladies  from  the  country,  who  were  not  used  to 
good  table  manners,  and  they  made  the  mistake 
of  pouring  the  tea  from  their  cups  out  into  their 
saucers  and  drinking  from  their  saucers.  Some 
of  the  other  guests  noticed  this  and  began  slyly 
to  laugh.  As  soon  as  the  king  saw  it,  he  im- 
mediately poured  the  tea  from  his  own  cup  out 
into  his  saucer  and  drank  from  his  saucer.  The 
other  guests  then  stopped  laughing  and  followed 
the  king's  example. 

Thus  the  two  ladies  were  saved  the  pain  of 
seeing  that  they  had  made  a  mistake.  But  it 
would  have  been  better  if  they  had  learned  and 
practiced  good  table  manners  at  home. 

THINGS    TO   FIND    OUT 

What  are  the  names  of  the  principal  dishes 
out  of  which  a  dinner  is  served  ? 

On  what  part  of  the  table  are  these  dishes 
placed  ? 


WHAT   WE   DRINK  33 

Show  by  a  drawing,  or  by  cutting  the  pieces 
out  of  paper,  how  the  plate,  knife,  fork,  spoon, 
napkin,  and  tumbler  should  be  placed  on  the 
table. 

What  are  some  of  the  most  important  rules 
of  table  manners  ? 

What  can  girls  do  to  help  their  busy  mothers 
about  getting  the  meals  ? 

What  can  they  do  toward  making  the  home 
pleasant  ? 

What  can  bo}^s  do  to  help  make  the  dinner 
hour  an  enjoyable  one  ? 

What  can  boys  or  girls  raise  in  the  garden  or 
window  garden  to  use  upon  the  table? 

WHAT   WE   DRINK 

WE  know  that  without  food  we  could  not  live 
long,  but  without  drink  we  could  not  live  even 
so  long  as  without  food.  Nature  has  provided 
us  with  a  drink  that  satisfies  all  our  needs,  and 
is  found  so  plentifully  that  all  may  have  enough. 

The  purest  water  is  the  rain  when  it  falls  from 
the  clouds.  After  it  falls  to  the  ground,  it  takes 
from  the  ground  over  which  or  through  which  it 

HALL'S  INT.  PHYS. — 3 


34 


PHYSIOLOGY 


flows  certain  minerals,  some  of  which  are  helpful 
and  others  of  which  are  harmful.  Water  which 
contains  lime  is  called  "  hard  water."  Rain  water 
has  no  lime  or  other  mineral  matter,  and  is  called 
"  soft  water."  People  usually  prefer  soft  water 
for  use  in  baths  and  in  washing  clothes.  Soft 


water  is  more  healthful  than  hard  water  for 
drinking.  It  is  these  minerals  that  give  to  the 
water  from  different  places  its  different  tastes. 
We  miss  the  minerals  from  the  rain  water,  and 
say  that  it  "  tastes  flat." 

In  the  country  people  get  wrater  from  wells 
sunk  into  the  ground.  If  the  wells  are  deep, 
and  from  one  hundred  to  two  hundred  feet  away 


WHAT  WE  DRINK  35 

from  any  foul  place,  such  as  a  barnyard  or  cess- 
pool, the  water  is  usually  pure.  No  foul  matter 
of  any  kind  should  ever  be  allowed  nearer  than 
this  to  the  well. 

In  the  cities,  water  is  usually  brought  into  the 
houses  through  lead  pipes.  When  water  stands 
in  such  pipes,  it  absorbs  some  of  the  lead,  which 
is  poisonous.  For  this  reason,  the  first  water 
drawn  from  the  faucet  after  it  has  stood  several 
hours  should  be  run  off  and  not  be  used  for  drink- 
ing or  cooking. 

Once  people  did  not  know  that  certain  diseases 
could  be  carried  from  one  person  to  another  in 
the  drinking  water.  Most  towns  or  cities  that 
have  a  public  water  supply  now  look  very  care- 
fully after  the  purity  of  the  water  that  is  carried 
to  the  people.  But  in  small  villages  and  country 
places  where  the  people  get  their  water  from 
wells,  sickness  is  often  caused  by  impurities  get- 
ting into  the  wells. 

During  the  recent  war  with  Spain,  a  company 
of  soldiers  were  encamped  in  New  York  State, 
near  a  farmhouse.  The  water  supplied  to  the 
soldiers  was  carefully  looked  after  and  treated  so 
that  it  was  safe  for  the  soldiers  to  drink.  But 


36  PHYSIOLOGY 

many  of  the  soldiers  liked  better  the  water  from 
the  well  near  the  farmhouse,  because  it  was  so 
cold.  By  and  by  typhoid  fever  began  to  break 
out  in  the  regiment.  The  physicians  examined 
the  water  that  had  been  given  the  men  and  found 
that  there  was  nothing  wrong  with  it.  Then  they 
questioned  the  sick  soldiers  and  found  that  every 
one  of  them  had  been  drinking  water  from  the 
farmhouse  well.  They  went  to  the  farmhouse 
and  found  that  some  one  there  had  been  ill  with 
typhoid  fever,  and  by  not  taking  proper  care  they 
had  allowed  the  germs  of  the  disease  to  get  into 
the  well. 

Another  story  has  been  recently  told  in  an 
English  medical  paper.  Typhoid  fever  broke  out 
in  a  certain  part  of  London.  The  people  who 
had  it  all  lived  in  the  same  neighborhood,  and  the 
doctors  soon  found  that  they  all  drank  water  from 
one  certain  well  in  that  place.  The  well  was 
examined,  and  near  it  was  found  a  broken  drain 
from  which  impurities  leaked  into  the  well.  A 
curious  part  of  this  story  was  that  there  were 
just  two  people  in  other  parts  of  the  city  who 
came  down  with  typhoid  fever  at  the  same  time, 
and  it  was  found  that  these  two  had  both  been 


WHAT  WE  DRINK  37 

drinking  water  from  that  same  well  in  the  neigh- 
borhood where  the  others  were  ill.  One  had  been 
there  visiting  friends,  and  the  other  was  an  old 
lady  who  had  moved  away  from  the  place  a  short 
time  before,  but  she  liked  the  water  from  the  old 
well  so  much  that  every  day  she  sent  there  for 
a  jug  of  it.  This  showed  very  clearly  that  the 
trouble  was  with  the  water  of  that  well. 

There  is  no  need  of  well  water  becoming  a 
source  of  danger  from  such  diseases,  if  people  only 
take  proper  care  to  prevent  it. 

We  must  look  after  not  only  the  water  supply, 
but  the  ice  supply  as  well.  A  cake  of  ice  looks 
so  clear  and  pure  that  it  hardly  seems  possible 
that  there  could  be  anything  harmful  in  it.  The 
purest  ice  is  artificially  frozen  and  made  from  dis- 
tilled water.  The  ice  is  made  from  day  to  day 
throughout  the  summer.  You  may  be  interested 
in  finding  out  how  men  can  make  water  freeze 
on  a  hot  day  in  midsummer. 

The  artificial  ice  does  not  supply  the  whole 
demand  for  this  cooling  and  refreshing  form  of 
water,  so  that  thousands  of  tons  of  ice  are  stored 
in  ice  houses  in  and  near  large  cities  during  the 
winter  to  be  sold  the  following  summer. 


38  PHYSIOLOGY 

Many  people  believe  that  freezing  purifies  water, 
but  such  is  not  the  case.  If  there  are  germs  of 
disease  in  the  water,  they  are  simply  put  to  sleep 
by  freezing,  only  to  awake  and  become  active  as 
soon  as  the  ice  melts. 

Great  care  is  taken  to  get  pure  water  perfectly 
free  from  the  germs  of  disease,  and  from  a  source 
not  easily  made  impure.  Equal  care  should  be 
taken  to  get  pure  ice.  Some  companies  cut  their 
ice  from  stagnant  ponds  or  from  rivers  where  the 
drainage  from  a  village  makes  it  impure.  Any 
disease  germs  that  may  be  in  it  are  thus  not  only 
brought  into  the  house,  but  actually  put  into  the 
refrigerator  with  the  food  supplies.  If  ice  water 
is  used  for  drinking,  portions  of  the  ice  are  put 
into  the  water  pitchers,  where  it  melts  and  makes 
the  water  impure. 

Every  person  should  be  just  as  careful  to  get 
pure  ice  as  he  is  to  get  pure  water  and  pure  milk. 

Water  forms  two  thirds  of  the  body,  and  enters 
into  everything  we  eat.  The  body  needs  about 
two  quarts  of  water  a  day,  and  about  half  of 
that  is  supplied  in  the  food.  Meat  and  vege- 
tables all  contain  water,  and  it  is  added  to  most 
of  the  things  which  we  cook.  Without  water 


WHAT  WE   DRINK  39 

our  lips  would  parch  and  our  bodies  would  dry 
up;  without  water  our  food  would  not  digest, 
the  blood  would  dry  up  in  our  veins,  and  we 
should  die.  People  sometimes  try  to  make  other 
drinks  take  the  place  of  water,  but  none  of  them 
can  do  the  work  which  water  does.  Some  drinks 
made  up  of  water  with  lemon  juice  or  other  fruit 
juice  added  are  very  healthful  and  cooling  for 
summer  drinks. 

Cereal  coffee  contains  food  as  well  as  water, 
and  makes  a  warm  drink  for  winter.  Coffee 
and  tea  ought  not  to  be  used  by  children  who 
want  to  grow  tall  and  be  strong  and  well.  There 
is  no  food  in  tea  and  coffee,  except  in  the  cream 
and  sugar  added.  These  drinks  make  children 
both  restless  and  cross,  often  taking  the  place 
of  nourishing  food  which  would  help  the  growth 
and  give  strength  to  the  body.  Children  cannot 
do  their  best  work  in  school  when  they  are  rest- 
less and  cross  and  not  well  fed.  If  you  have 
not  used  coffee  and  tea  it  will  be  well  for  you 
never  to  begin.  If  you  have  already  begun,  make 
a  change  and  try  how  well  you  feel  when  you 
drink  water,  milk,  or  cereal  coffee. 

In  drinking  at  meal  times  it  is  well  to  take 


40  PHYSIOLOGY 

water  that  is  not  ice  cold,  and  to  take  it  toward 
the  last  of  the  meal  rather  than  at  first.  Ice 
water  is  less  healthful  than  simple  cold  water. 
If  taken  at  all  it  should  be  sipped  slowly  enough 
to  allow  it  to  become  warm  before  it  reaches 
the  stomach.  Children  sometimes  come  in  from 
play  very  hot  and  thirsty  and  drink  a  good  deal 
of  water.  It  would  be  better  to  drink  less  at  a 
time  and  be  very  careful  that  it  is  not  too  cold. 
Many  people  have  lost  their  lives  through  drink- 
ing very  cold  water  when  overheated. 

What  do  horses  and  cows  drink  ? 

What  do  young  kittens  and  puppies  drink? 

What  do  birds  drink  ?     What  do  plants  drink  ? 

Where  does  your  village  or  neighborhood  get 
its  water  supply?  Is  this  water  soft  or  is  it 
hard? 

WHAT   THE   MOUTH   DOES   TO   HELP  IN 
DIGESTION 

CAN  you  bring  to  mind  the  picture  of  the 
town  upon  which  we  looked  from  the  hilltop? 

Do  you  remember  the  mill  which  ground  the 
grain  into  flour  before  it  was  distributed  to  the 
different  parts  of  the  town  ?  The  body  has 


THE  MOUTH  AND  DIGESTION  41 

something  that  does  for  it  what  the  mill  does 
for  the  town.  With  a  mirror  you  can  look 
into  the  mouth  and  see  how  it  is  arranged  for 
cutting  and  grinding  the  food. 

Can  you  count  your  teeth?  Children  under 
six  years  have  but  twenty  teeth,  but  at  that 
age  the  teeth  begin  to  loosen  and  come  out, 
and  the  second  set  of  thirty-two  teeth  conies  in. 
The  front  ones  are  for  cutting,  and  the  back 
ones  for  grinding.  These  teeth  must  last  a  life- 
time, for  no  others  will  take  their  place  when 
they  come  out. 

As  we  shall  need  teeth  as  long  as  we  shall 
need  food,  and  as  no  others  can  ever  do  the 
work  of  the  real  teeth,  it  will  be  best  to  take 
as  good  care  of  them  as  is  possible,  and  keep 
them  as  long  as  we  can. 

The  first  thing  toward  caring  for  the  teeth  is 
to  eat  bone-making  food.  Do  you  remember 
what  are  the  best  bone-making  foods  ?  Then  we 
must  see  that  none  of  the  food  remains  on  the 
teeth  and  spoils  them.  The  little  particles  of 
food  can  be  taken  from  between  the  teeth  with 
a  toothpick,  never  with  a  hard  body,  such  as  a 
needle  or  a  pin;  the  toothbrush  used  once  or 


42  PHYSIOLOGY 

twice  a  day  will  take  off  all  that  gathers  on  the 
outside. 

The  dentist  should  have  charge  of  the  teeth, 
and  by  seeing  them  every  year  he  will  care  for 
each  cavity  when  it  first  appears,  and  prevent 
both  toothache  and  the  loss  tof  teeth. 

Think  of  something  which  you  like  to  eat, 
strawberries  or  oranges,  for  example,  and  see 

how  the  saliva  flows  into 
your  mouth.  Even  the 
thought  of  food  makes 

STRAWBERRIES.  ^       gajjva      flQW?       an(J 

when  the  food  itself  enters  the  mouth,  the  saliva 
flows  very  freely,  making  the  food  moist  and 
easy  to  chew  and  swallow. 

It  is  necessary  to  chew  the  food  long  enough 
to  make  it  very  fine,  and  to  allow  the  saliva  to 
get  to  every  part  of  it.  Sips  of  water  taken 
while  the  food  is  in  the  mouth  wets  the  food  so 
much  that  it  does  not  get  enough  saliva  to 
digest  it. 

If  food  is  well  chosen,  well  cooked,  eaten  at 
the  right  time,  and  well  chewed,  we  need  give 
it  no  further  thought,  because  the  stomach  and 
other  digestive  organs  will  take  care  of  it. 


HOW  THE  FOOD  IS  SWALLOWED  43 

HOW   THE   FOOD  IS   SWALLOWED 

WHEN  the  food  is  ready,  the  tongue  pushes  it 
back  into  the  passage  from  which  doors  open 
into  other  passages.  There  is  an  opening  for 
the  food,  one  for  the  air  to  go  into  the  lungs, 
and  one  by  which  the  air  comes  in  from  the 
nose.  If  there  were  no  doors,  the  food  might 
sometimes  go  up  into  the  nose  or  down  into 
the  windpipe. 

When  we  swallow,  the  door  (epiglottis)  over 
the  windpipe  shuts  down  and  closes  the  pas- 
sage, and  a  heavy  muscle-curtain  (soft  palate  and 
uvula)  swings  back  against  the  nose  passage.  If 
you  laugh  and  swallow  at  the  same  time,  the  door 
into  the  windpipe  does  not  close,  and  you  will  have 
to  cough  until  the  food  which  got  into  the 
windpipe  can  be  coughed  out  again.  Sometimes 
when  the  throat  is  much  swollen,  milk  or  water, 
which  cannot  go  down  into  the  stomach,  will 
come  out  through  the  nose.  If  you  look  at  the 
picture,  you  will  see  where  each  of  these  pas- 
sages opens  into  the  large  one,  and  see  the  doors. 

Find  out  how  a  bird  swallows  water.  How  can 
a  snake  swallow  a  frog  larger  than  his  own  head  ? 


44 


PHYSIOLOGY 


HOW   THE   FOOD   IS   DIGESTED 


the  food  is  swallowed  it  passes  down 
through  a  long  tube  —  the  esophagus  —  (see 
Fig.  1)  and  empties  into  the  stomach. 


FIG.  1. — Picture  showing  the  pharynx  (8)  into  which  the  food  empties 
from  the  mouth  (3).  The  door  over  the  windpipe  (12)  is  the  epi- 
glottis (9).  The  uvula  (4)  is  the  muscle-curtain  over  the  nose 
passage  (2). 


HOW   THE   FOOD  IS   DIGESTED 


45 


The  stomach  (see  Fig.  2)  is  the  storehouse  for  the 
food  and  is  the  place  where  the  food  is  prepared  for 
use.  The  end  of  ESOPHAGUS-! 

the  stomach,  into 
which  the  food 
first  empties,  is 
the  storehouse 
part,  and  here 
the  food  is  held, 
mixed  with  gas-  | 
trie  juice,  and 
then  given  out 
at  the  other  end 
as  it  is  ready. 
When  it  goes  to 
the  small  end  of 
the  stomach  it 
is  churned  and 

mixed    with     the     FlG<  2.  -  THE  DIGESTIVE  TUBE  OR  CANAL. 

gastric  juice,  which  softens  and  changes  it  until  it 
is  "digested,"  we  say. 

But  the  stomach  cannot  digest  everything  that 
comes  into  it;  so  that  after  doing  all  that  it 
can  it  passes  the  food  on  to  a  long  tube — the  intes- 
tine—  that  has  a  different  kind  of  juice,  which  can 


46  PHYSIOLOGY 

complete  the  digestion.  This  tube  is  very  long, 
but  is  coiled  round  and  round  so  that  it  takes 
up  very  little  room.  In  the  intestine  the  food  be- 
comes almost  as  thin  as  water  and  looks  milky. 
It  is  then  ready  to  leave  the  intestine. 

Up  to  this  time,  although  the  food  is  inside  of 
the  body,  it  is  not  a  part  of  it,  but  when  it  leaves 
the  intestine  it  becomes  a  real  part  of  the  body= 

HOW  THE  FOOD  IS  TAKEN  UP   FROM   THE 
INTESTINE 

ALL  along  the  inside  of  the  intestine  are  tiny 
tubes  and  blood  vessels  into  which  the  food  oozes 
through  the  thin  skin  that  covers  them.  The 
little  tubes,  called  lacteals,  lead  to  the  blood  ves- 
sels, and  empty  this  new  material  into  the  blood. 
All  that  has  been  eaten  which  does  not  make 
blood  is  carried  through  the  small  intestine  down 
into  the  large  intestine  to  be  cast  out. 

HOW   TO   TAKE   CARE   OF   THE   STOMACH 

THE  more  we  eat  that  is  digestible,  the  more 
rich  blood  we  make.  The  more  we  eat  that  is 
indigestible,  the  more  waste  material  we  have. 


HOW  TO  TAKE  CARE  OF  THE  STOMACH    47 

The  more  waste  material  there  is,  the  more  work 
the  body  does  for  nothing.  The  more  unneces- 
sary work  the  stomach  does,  the  more  quickly 
it  will  get  out  of  order. 

The  stomach  and  intestine  should  not  be  made 
to  work  all  the  time,  for  they  will  surely  wear 
out  if  they  do.  If  food  is  eaten  at  regular  .times 
and  is  of  a  kind  that  does  not  take  too  long  to 
digest,  the  stomach  can  get  its  work  for  each 
meal  done  in  two  or  three  hours  and  have  time 
to  get  well  rested  before  the  next  meal.  If  in- 
digestible food  is  eaten  or  if  food  is  taken  between 
meals,  there  is  either  no  resting  time  at  all  or 
not  enough,  and  the  stomach  becomes  too  tired 
to  do  good  work. 

Children  sometimes  think  that  they  ought  not 
to  eat  anything  which  they  do  not  like,  and  they 
are  not  willing  to  give  up  eating  things  which 
they  do  like;  but  childhood  is  the  time  to  form 
tastes.  Is  it  not  better  to  choose  those  things 
which  are  for  the  best  good  of  the  body,  and  do 
without  those  things  which  do  us  either  no  good 
or  do  us  harm? 

g  Many  people  think  that  a  drink  of  cocoa,  choco- 
late, or   milk  in  the   middle  of  the  forenoon  or 


48  PHYSIOLOGY 

afternoon  can  do  them  no  harm.  Many  people 
eat  ice  cream  and  cake,  or  candy  and  fruit,  between 
meals.  All  of  the  things  here  mentioned  are  foods 
which  require  digestion.  It  is  just  as  hard  for  the 
stomach  to  digest  chocolate  or  milk  as  it  is  to 
digest  eggs  or  bread.  Milk  and  chocolate  are 
liquid  foods.  They  do  not  quench  the  thirst.  All 
of  the  things  just  mentioned  should  be  taken  at 
meal  time  only,  if  one  wishes  to  take  the  best  care 
of  the  stomach. 

The  stomach  and  the  whole  body  may  be  injured 
by  foods  or  drinks  taken  at  meal  time.  Many 
children  drink  coffee  or  tea  with  their  meals. 
Coffee  or  tea  never  does  grown  up  people  any 
good;  and  they  do  harm  to  many  people.  These 
drinks  always  injure  children.  Professor  Spade 
of  Wilmington,  Delaware,  writing  for  the  Journal 
of  Education,  says :  "  Poor  ventilation  is  not  re- 
sponsible for  all  the  dullness  and  headaches  among 
school  children.  In  our  school  of  two  hundred 
children  at  least  one  hundred  and  seventy  were 
found  to  be  tea  and  coffee  drinkers.  And  the 
habit  was  so  strongly  fastened  upon  some  of  them 
that  they  could  not  well  do  without  coffee  for  one 
day.  If  people  only  knew  how  much  headache 


HOW  THE  FOOD  IS  TAKEN  UP  BY  THE  BODY   49 

and  other  trouble  the  use  of  tea  and  coffee  pro- 
duces, a  mighty  crusade  would  be  made  against 
their  use." 

They  are  positively  injurious  to  children  and 
young  people,  and  many  persons  beyond  middle 
life  would  be  much  better  off  without  them. 

If  people  knew  how  much  these  drinks  injure 
a  child  or  young  person  they  would  not  have  them 
upon  the  table.  Many  families  are  now  using 
such  drinks  as  Postum  Cereal  or  Grain-o.  These 
cereal  coffees  are  nourishing  and  they  do  not  injure 
the  digestion,  cause  headaches,  or  make  one  nervous 
or  irritable. 

In  the  time  of  our  grandfathers  children  drank 
water  at  the  table.  The  more  we  study  these 
questions  about  what  is  best  to  eat  and  drink, 
the  more  certain  it  is  that  there  is  no  drink  so 
healthful  for  children  and  for  grown  up  people 
as  pure  water. 


HOW  THE  FOOD  IS  TAKEN  UP  BY  THE 
BODY 

CAN  you  imagine  a  tube  about  twenty  feet  long 
and  an  inch  through,  made  of  such  soft  skin  that 

HALL'S  INT.  PHTS.  — 4 


50 


PHYSIOLOGY 


it  can  be  doubled  up  any  way  without  hurting 
it  ?  If  so,  you  can  think  just  about  how  the 
small  intestines  look  doubled  up  so  that  they 
go  into  a  space  less  than  a  foot  square.  Look 
at  Figure  2  and  you  will  see  just  how  the  coils 
are  made. 

The  whole  inside  of  this  tube,  instead  of  being 

smooth  like  a  rubber 
hose,  has  a  soft  skin 
that  has  ridges  cross- 
wise of  it.  The  food 
in  passing  along 
through  the  tube  has 
to  go  over  all  these 
ridges.  But  even 

FIG.   3.  —  A  PIECE    OF   THE    INTESTINE 

(showing  the  villi  at  the  opening  of  the    this     IS     not     all     the 
piece).  —  [TRACY.]  . 

roughness  01  the  in- 
side of  the  tube,  for  on  all  of  the  ridges  are  little 
points,  or  villi,  sticking  up  into  the  tube. 

You  can  see  that  the  food  will  not  move  so  fast 
through  a  tube  of  this  kind  as  it  would  through  a 
smooth  one,  and  that  is  one  reason  why  it  is 
rough. 

We  have  already  spoken  of  the  tiny  tubes  or 
lacteals  in  the  small  intestine  which  take  up  the 


HOW  THE  FOOD  IS  TAKEN  UP  BY  THE  BODY   51 


food.  These  tubes  run  up  into  the  points,  or  villi, 
which  project  into  the  intestines.  In  the  picture 
(Fig.  3  )  you  can  see  one  row  of  villi  ;  really  the 
whole  inside  of  the  small  intestine  is  provided  with 
these  villi.  In  Figure  4  you  can 
see  how  these  villi  look  when 
magnified.  In  every  villus  there 
is  a  tube  in  the  middle  around 
which  are  loops  of  blood  vessels. 
As  the  food  passes  slowly 
along  the  intestines,  the  part 
that  is  digested  soaks  through 
the  thin  skin  over  the  tiny  lac- 
teals  or  into  the  small  blood 
vessels  which  surround  it. 


All  of  the  starch  foods  change  FIG.  4.—  A  VILLUS, 

NIFIED. 

to   sugar,  and   the  sugar  foods  sk,  skin  through  which 

i_  TJ.,I          the  food  soaks  ;  bv,  the 

are     taken     up    by    the    little     loop  of  blood  vessels; 

.  lac,  the  lacteals. 

blood     vessels    and     flow     into  —[TRACY.] 

larger  blood  vessels  which  carry  them  to  the  liver. 

The  liver  is  a  large  organ  that  fills  up  the  most 
of  the  upper  part  of  the  abdomen,  and  is  the  body 
storehouse  for  sugar. 

This  wonderful  organ  can  store  up  sugar  and 
give  it  out,  a  little  at  a  time,  as  it  is  needed  and 


52 


PHYSIOLOGY 


called  for  by  the  body.     From  the  liver  the  food 

goes  with  the  blood  to  the  right  side  of  the  heart. 

The  fat  foods  in  the  intestines  are  taken  up  by 

the  villi  into  the  little  lacteals  (see  Fig.  5),  which 

empty  into  larger 
lacteals,  and  are 
carried  by  a  large 
tube  up  to  the  left 
side  of  the  neck 
and  emptied  into  a 
vein,  and  so  become 
a  part  of  the  blood. 
The  meat  foods  are 
taken  up  by  both 
the  lacteals  and  the 
blood  vessels  in  the 
same  way  as  already 
described.  Now  we 

a,  portal  vein ;  6,  g,  thoracic  duct ;  c,  groups 
of  lacteals;  d,e,  intestine;  /,  lacteals.—   have        traced        the 

[JOHONNOT   &   BOUTON,  p.  59.1  /•          i     c  i 

food  from  the  place 

where  it  grew  to  the  place  where  it  becomes  a  part 
of  the  blood. 

Do  birds  chew  their  food  ?  If  not,  how  do  they 
grind  the  hard  grains  of  wheat,  corn,  and  oats 
which  they  eat  ? 


9       f 

FIG.  5.  —  THE  LACTEALS  AND  THEIR 
CONNECTIONS. 


HOW  THE  FOOD  IS  USED  BY  THE  BODY    53 

HOW  THE  FOOD  IS  USED  BY  THE  BODY 

IF  you  think  back  to  the  lesson  on  "  Why  we 
Eat,"  you  will  remember  that  we  had  to  have  food 
to  replace  the  worn-out  material,  to  add  new  mate- 
rial, and  to  keep  the  body  warm. 

Most  of  the  food  which  we  eat  and  which  is 
taken  up  into  the  blood  and  distributed  over  the 
body  is  used  by  the  muscles.  The  work  of  the 
muscles  is  to  warm  the  body  and  to  make  the  move- 
ments of  the  body.  The  food  is  the  fuel  of  the 
body,  and  is  used  mostly  by  the  muscles  in  this 
work.  The  fuel  of  the  engine  is  burned  quickly 
and  burned  with  a  flame ;  but  the  food  is  burned 
slowly  and  without  any  flame  in  the  body. 

All  the  while,  both  day  and  night,  food  is  being 
used  in  the  muscles  as  we  use  coal  in  the  furnace. 
Just  how  the  food  is  burned  in  the  body  will  be 
described  in  a  later  lesson  on  "  How  the  Body  is 
Warmed." 

The  muscles  and  such  organs  as  the  liver, 
stomach,  and  brain,  which  do  the  work  of  the 
body,  need  food  to  feed  and  strengthen  them  for 
their  work. 

They  find  this  food  in  the  blood,  and  as  the 


54 


PHYSIOLOGY 


blood  circulates  through  them  each  takes  just  the 
kind  and  the  amount  of  food  that  it  needs. 

In  growing  children,  every  part  of  the  body 
must  take  up  food  from  the  blood  to  add  to  its 
size  as  well  as  to  replace  the  loss. 


What  happens  to  plants  when  there  is  no  rain 
for  a  long  time  in  midsummer  ? 

Which  could  a  person  do  without  longest,  food 
or  water  ? 

Every  person  and  animal  needs  either  lean  meat 
or  the  albumen  found  in  eggs  and  milk  and  beans 
and  peas  and  the  cereals. 


SOME  THINGS  THAT  HARM  THE  BODY    55 

Every  person  and  animal  needs  either  fat  or 
sugar  or  starch.1 

What  does  a  horse  eat ;  and  where  does  he  get 
albumen?  Where  does  the  horse  get  fat,  or  sugar, 
or  starch  ? 

Find  out  all  you  can  about  the  food  of  the  fox ; 
the  bear ;  the  sheep  ;  the  elephant ;  the  tiger ;  the 
giraffe ;  the  antelope ;  the  deer. 

SOME  THINGS  THAT  HARM  THE  BODY 

WE  have  read  about  the  good  which  the  fresh 
ripe  fruits  do  the  body  and  what  cooling  drinks 
can  be  made  from  fruit  juice  and  water ;  but  great 
harm  can  be  done  by  fruit  juice  when  it  is  not 
fresh. 

The  fruit  with  its  juice  was  once  a  part  of  a 
living  plant.  When  fruit  ripens,  it  usually  falls 
from  the  plant  and  soon  begins  to  go  to  pieces. 
This  is  the  way  with  all  living  things.  They  live 
for  a  time,  then  die  and  go  to  pieces  or  decay.  If 
it  were  not  for  this  falling  to  pieces,  the  earth 

1  Grass  and  hay  and  other  herbage  contain  cellulose,  which  is 
very  nearly  the  same  as  starch,  and  can  be  changed  to  sugar  in 
the  digestive  tube  of  the  herbivorous  animals,  such  as  the  sheep, 
the  cow,  and  the  horse. 


56  PHYSIOLOGY 

would  be  so  crowded  with  dead  forms  that  there 
would  be  no  room  for  new  living  growths. 

But  this  decay,  or  falling  to  pieces,  does  not  go 
on  without  means.  There  are  multitudes  of  small 
living  things,  too  small  to  be  seen  by  the  naked 
eye,  whose  life  work  is  to  destroy  things  from 
which  life  has  gone. 

When  grapes  or  apples  are  ripe  and  fall  to  the 
ground,  they  soon  begin  to  rot  and  go  to  pieces. 
This  rotting  may  be  caused  by  plants  too  small 
to  be  seen  without  a  microscope.  These  plants 
that  cause  fruits  to  rot  are  called  molds  or  bac- 
teria. Some  kinds  of  them  form  the  mold  that 
you  sometimes  see  on  old  bread  and  cheese. 

If  the  apples  or  grapes  are  not  left  to  rot,  but 
are  gathered  and  crushed,  and  the  juice  pressed 
out,  this  juice  ceases  to  be  a  part  of  living  matter, 
and  will,  unless  prevented,  begin  to  decay.  This 
decay  in  the  pressed-out  fruit  juice  is  started 
by  little  plants  called  yeast  plants  or  ferments. 
They  are  different  from  those  that  cause  the 
whole  fruit  to  decay.  These  yeast  plants  were 
on  the  outside  of  the  ripe  fruit  before  it  was 
crushed.  When  the  juice  was  pressed  out,  the 
yeast  plants  were  washed  into  it,  and  in  a  very 


SOME  THINGS  THAT  HARM  THE  BODY          57 

few  hours  they  started  the  process  of  decay  in 
the  following  manner :  — 

The  juice  as  it  comes  from  the  ripe  fruit  is 
sweet  because  there  is  sugar  in  it.  The  yeast 
plants  cause  the  sugar  to  change  into  two  new 
substances,  a  gas  and  alcohol.  The  gas  passes 
off  in  tiny  bubbles,  but  the  alco- 
hol remains.  The  alcohol  is  a 
poison.  A  poison  is  any  sub- 
stance whose  nature  it  is  when 
absorbed  into  the  blood  to  injure 
health  or  destroy  life. 

If  we  did  not  know  about  the 
yeast  plant  and  what  it  does,  we 
might  wonder  how  there  could 
be  anything  harmful  in  cider,  FlG  6._YKAST 
which  is  the  juice  of  apples,  and  CELLS  (x50°)< 
wine,  which  is  the  juice  of  grapes,  when  apples 
and  grapes  themselves  are  so  healthful.  If  the 
juice  of  apples  and  grapes  is  used  as  soon  as  it 
comes  from  the  fruits,  or  if  it  is  cooked  and  bot- 
tled right  away,  it  contains  nothing  harmful  and 
is  indeed  refreshing  and  healthful;  but  as  soon 
as  the  yeast  plant  has  time  to  work  in  it,  and 
that  is  only  a  few  hours  after  it  is  made,  the 


58  PHYSIOLOGY 

sugar  begins  to  change  to  gas  and  alcohol.  If  one 
needs  the  acid  of  fruit  juices  he  can  get  it  in  its 
best  state  fresh  from  the  fruit,  either  by  eating 
the  fruit  or  by  pressing  out  the  juice  and  using 
it  before  it  ferments.  It  is  a  law  that  fermentation 
changes  the  nature  of  the  substance  it  works  upon, 
and  fruit  juice  that  has  fermented  has  a  different 
nature  from  the  juice  as  it  comes  from  the  fruit. 
It  is  a  false  idea  that  it  is  well  to  drink  cider  for 
the  acid  it  contains.  It  is  better  to  get  the  acid 
fresh  from  the  fruit  without  the  poison  that  comes 
from  the  fermentation  of  the  apple  juice.  Cider, 
wine,  beer,  brandy,  and  whisky  all  contain  alcohol 
and  are  harmful. 

A  longing  for  water  is  thirst  and  a  longing  for 
food  is  hunger,  but  a  longing  for  that  which  is 
neither  water  nor  food  is  neither  thirst  nor  hunger, 
but  desire.  One  cannot  have  a  thirst  for  alcohol, 
but  he  can  have  a  desire  for  it. 

Drinking  alcoholic  drinks  does  not  satisfy  this 
desire,  but  creates  a  still  greater  desire.  That  is 
why  people  find  it  so  hard  to  stop  using  it  after 
having  once  begun.  There  is  but  one  way  to  keep 
from  having  a  desire  for  strong  drink,  and  that  is 
not  tp  take  the  first  drink.  One  drink  may  con- 


SOME  THINGS  THAT  HARM  THE  BODY    59 

tain  but  little  alcohol,  but  alcohol  has  the  power, 
though  taken  in  small  quantities,  to  create  a 
desire  for  more ;  and  this  desire  may  become 
uncontrollable. 

This  desire  for  drink  does  not  grow  with  the 
same  rapidity  upon  all.  Many  do  not  realize  that 
they  have  such  a  desire  until  it  becomes  stronger 
than  their  will  to  resist  it.  Thus  the  drinker 
becomes  a  slave  before  he  is  aware.  No  one  ex- 
pects to  become  a  drunkard  when  he  first  begins 
to  drink.  Every  one  who  begins  is  starting  out 
over  the  same  road  that  every  drunkard  once 
traveled 

People  who  do  not  know  about  the  power  that 
a  little  alcohol  has  to  create  a  desire  for  more 
sometimes  use  it  as  a  flavoring  for  pudding  sauces 
and  other  articles  of  food.  There  are  plenty  of 
other  flavorings  that  have  not  this  danger.  No 
kind  of  alcoholic  liquor  is  needed  as  a  flavoring 
in  any  kind  of  food  and  none  should  ever  be  used. 

The  juices  of  ripe  fruits,  such  as  grapes,  currants, 
and  raspberries,  may  be  made  into  delicious  and 
healthful  drinks  by  heating  them  as  soon  as  they 
are  pressed  out  and  sealing  them,  while  boiling 
hot,  in  air-tight  jars  or  bottles.  But  if  the  juice 


60  PHYSIOLOGY 

is  allowed  to  stand  and  ferment  after  it  is  pressed 
out,  as  is  the  case  with  the  drinks  called  "  home- 
made "  wines,  there  will  be  alcohol  in  it.  No  one 
who  understands  the  nature  of  alcohol  and  is  truly 
wise  will  make  or  use  any  drink  containing  it. 

When  we  put  yeast  into  bread  dough  to  make 
it  rise,  the  yeast  acts  upon  the  free  sugar  that  the 
flour  contains  and  changes  that  to  alcohol  and  gas. 
The  gas  forces  its  way  through  the  dough,  and  in 
doing  so  puffs  up  the  dough  and  makes  the  bread 
light.  But  the  alcohol  is  changed  to  a  vapor  by 
the  heat  and  passed  out  of  the  dough  while  the 
bread  is  baking.  Thus  we  can  use  yeast  in  making 
bread,  and  get  light  bread  and  no  alcohol,  because 
the  alcohol  is  driven  off  by  the  heat. 

Alcohol  has  other  bad  effects.  It  inflames  the 
lining  of  the  stomach,  and  then  the  stomach  not 
only  gives  pain,  but  it  cannot  do  its  work  of 
digesting  the  food  well. 

Some  people  think  a  little  wine  or  other  strong 
drink  after  a  meal  helps  to  digest  it.  That  is  a 
mistake.  Instead  of  removing  any  trouble  caused 
by  indigestion,  it  dulls  the  feeling  of  pain  so  that 
people  go  on  eating  indigestible  foods  without 
knowing,  until  too  late^  the  harm  they  are  doing. 


SOME   THINGS  THAT   HARM  THE   BODY         61 

Beer  contains  alcohol,  and  it  can  do  harm  the 
same  as  the  stronger  drinks,  except  that  it  takes 
more  beer  than  whisky  to  injure  a  person  seri- 
ously. 

The  stronger  alcoholic  drinks  are  whisky, 
brandy,  and  rum.  These  drinks  are  nearly  one 
half  alcohol. 

Some  people  think  that  these  alcoholic  drinks 
make  them  stronger ;  but  the  fact  is  that  all 
drinks  which  contain  alcohol  make  one  less 
strong,  less  quick,  and  less  alert.  For  this  rea- 
son athletes  are  never  allowed  to  have  any  of 
these  drinks  when  they  are  training  for  a  con- 
test. 

Root  beer  is  sometimes  made  from  material 
sold  by  druggists.  If  yeast  is  used  in  making 
the  root  beer,  bubbles  of  gas  will  escape  from  the 
liquid,  and  alcohol  will  be  formed  and  will  remain 
in  the  root  beer.  Root  beer  made  in  this  way 
may  lead  to  a  desire  for  stronger  drinks,  and 
is  not  a  safe  beverage. 

TOBACCO 

A  narcotic  is  a  substance  which,  taken  into 
the  system,  dulls  the  senses.  The  senses  are 


62  PHYSIOLOGY 

hearing,  seeing,  smelling,  tasting,  and  feeling; 
and  all  of  these  senses  are  made  less  sharp  by 
a  narcotic.  Alcohol  and  tobacco  are  narcotics. 

Tobacco  is  made  from  the  leaf  of  the  tobacco 
plant.  It  contains  a  poison  so  deadly  that  if 
much  were  swallowed  it  would  cause  death.  In 
smoking,  none  of  the  tobacco  juice  is  swallowed, 
but  the  smoke  itself  is  very  harmful.  In  chew- 
ing, some  of  the  poison  gets  into  the  system, 
although  the  chewer  tries  to  spit  it  out. 

While  tobacco  harms,  to  some  extent,  every 
one  who  uses  it,  it  does  greatest  harm  to  the 
young  person  who  is  growing.  A  boy  who  uses 
tobacco,  either  in  cigars  or  cigarettes,  seldom 
grows  to  the  size  that  he  might  have  grown,  or 
is  able  to  think  so  clearly  as  he  might  have  done. 
Still  worse,  the  poison  makes  him  not  even  care 
that  he  is  not  doing  the  best  that  he  might  do. 

Another  narcotic  which  does  great  harm  is 
opium.  The  soothing  syrups  which  some  mothers 
and  nurses  give  to  their  babies  to  quiet  them  con- 
tain opium.  It  quiets  the  child  because  it  dulls 
his  brain  and  puts  him  to  sleep,  but  it  may  injure 
his  brain  all  through  life.  Doctors  tell  us  that  the 
cause  of  many  weak  and  disordered  brains  is  the 


THE   BLOOD 


63 


soothing  syrup  taken  in  childhood.  To  get  a  few 
hours'  release  from  caring  for  the  baby,  by  giving 
him  a  drug  that  will  injure  his  brain  for  life,  is  a 
very  selfish  practice. 

THE   BLOOD 

WE  have  all  seen  blood,  and  know  that  it  is 
red  and  thicker  than  water.  As  we  look  at  it, 
it  seems  to  be  alike 
all  through ;  but 
when  we  put  a  drop 
on  a  glass  and  look 
at  it  through  a 
microscope,  we  find 
that  it  looks  like 
water  with  many 
little  red  and  white 
particles  floating  in 
it  (see  Fig.  7). 

There  are  really 
three  parts  to  the 
blood:  the  colorless, 
watery  part ;  the 
red  particles,  flat  and  round,  called  red  corpuscles ; 
and  the  larger  rough,  white  spheres  called  white 


FIG.  7.  —This  shows  the  way  a  tiny  drop  of 
blood  would  look  if  spread  upon  a  glass 
plate  and  viewed  under  a  high-power 
microscope.  Each  red  corpuscle  is  a  disk 
which  is  thicker  around  the  edge  than  in 
the  middle.  One  of  these  disks  is  shown 
from  the  side  (s).  The  large  spherical, 
granular  body  is  a  white  or  colorless 
corpuscle. 


64  PHYSIOLOGY 

* 
corpuscles.     Each  of  these  parts  of  the  blood  has 

a  separate  work  to  do  in  its  own  way. 

The  thin,  watery  part  of  the  blood  is  the  food 
which  soaked  through  into  the  veins  from  the 
intestine,  and  contains  all  the  good  part  of  what 
is  eaten  and  much  of  the  water  which  one  drinks. 

There  are  so  many  of  the  red  corpuscles  float- 
ing in  the  blood  that  they  make  the  whole  blood 
look  red.  As  the  boats  carry  coal  down  the 
river,  so  these  red  corpuscles  carry  a  load  of  oxy- 
gen through  the  blood  from  the  lungs  to  the 
tissues.  When  they  give  up  their  oxygen  to 
the  muscles  and  brain  and  glands,  these  cor- 
puscles lose  their  bright  color  and  become  a 
dark  purplish  color,  until  they  get  another  load 
of  oxygen  from  the  lungs.  Oxygen  is  the  part 
of  the  air  which  the  body  uses. 

The  white  corpuscles  are  like  the  police  force 
of  the  town,  and  keep  the  body  from  much  harm 
that  would  otherwise  come  to  it.  If  a  thorn 
gets  into  the  body,  these  little  white  corpuscles 
hurry  to  the  place,  gather  around  the  thorn, 
and  keep  it  from  doing  further  injury  to  the  body, 
and  at  last,  by  causing  the  place  to  "  fester,"  they 
push  it  out. 


THE   BLOOD  65 

If,  in  our  town  water  system,  a  hole  is  made 
in  one  of  the  pipes,  the  water  keeps  running 
until  the  hole  is  mended ;  but  if  a  similar  thing 
were  true  in  our  bodies,  we  might  die  before 
the  leak  could  be  stopped.  When  the  finger  is 
cut  the  blood  runs,  sometimes  very  fast  at  first, 
but  soon  more  slowly,  and  after  a  time  it  stops 
running  altogether. 

In  some  way  when  blood  is 
open  to  the  air  it  thickens,  and 
this  thickened  blood  fills  up  the 
cut  and  stops  the  flow  of  blood. 

The  blood  will  thicken  more 
quickly  by  the  use  of  hot  water,  while 
cold  water  will  make  it  flow  longer. 

If  a  large  vein  or  artery  is  cut,  the 
blood  runs  so  fast  that  one  would  soon  lose 
enough  blood  to  cause  death  if  the  wound  were 
not  tied  up. 

If  one  wants  good  red  blood,  he  must  eat  good 
healthful  food,  take  plenty  of  exercise,  and  breathe 
plenty  of  fresh,  pure  air. 

Rich,  pure  blood  gives  the  red  color  to  lips  and 
cheeks,  the  strength  to  the  body,  and  the  power  to 
think  well. 

HALL'S  INT.  PHYS. — 5 


66 


PHYSIOLOGY 


HOW  THE  BLOOD  IS  CARRIED  OVER  THE  BODY 

Let  us  take  another  look  at  our  town,  and  again 
notice  the  great  system  of  pipes  going  out  from 

the  pumping  sta- 
tion, carrying  fresh 
water  to  every  part 
of  the  town,  then  in- 
to every  house,  and 
at  last  to  different 
parts  of  each  house, 
where  we  shall 
find  another  system 
of  pipes  gathering 
up  from  each  house 
the  waste,  which  is 
then  emptied  into 
larger  pipes,  and 
later  into  the  main 
sewer,  to  be  carried 

A,  the  right  side,  which  receives  Impure  ,  r 

blood  from  the  little  chamber  C.  *°  SOme  streain  oi 

B  the  left  side,  which  receives  pure  blood  t  which  m 
from  the  chamber  D. 

E,  the  large  artery  carrying  pure  blood  carry    it    to    the   SCa, 
from  the  heart  to  the  body. 

F,  the  large  artery  carrying  impure  blood    where      it      Will      be 
from  the  heart  to  the  lungs  to  be  purified. 

— [JOHONNOT&  BOUTON,  p.  7i.]  made  pure  again. 


FIG.  8. —THE  HEART. 


THE  BLOOD 


67 


If  you  bring  this  all  to  mind  again,  it  will  help 
you  to  understand  the  two  great  systems  of  pipes 
in  our  bodies. 

The  heart  (see  Figs.  8  and  9),  although  not 
larger  than  the  closed  hand,  is  the  pump  which 
sends  the  stream  of 
blood  over  the  body. 

From  the  left  side 
of  the  heart  are  large 
tubes  or  arteries  which 
soon  divide  and  send 
branches  to  the  head, 
one  to  each  arm,  one 
to  each  leg.  These 
all  divide  again  and 
again,  until  there  are 
a  great  number  of 

.       FIG.  9.  —  This  shows  the  way  the  heart 

Very    tiny    arteries    in       is  partitioned  off  inside.    See  if  you 
£      ,1  can  trace  the  course  of  the  blood  after 

every    part     of    the     it  enters  the  right  auricle  ^  toe 

body.        If     yOU    look       body.- [TRACY,  149.] 

at  the  picture  (Fig.  10),  you  will  understand  better 
how  these  arteries  look. 

Every  time  the  heart  beats,  it  pumps  the  blood 
through  all  these  large  pipes  into  the  smaller 
ones,  and  finally  into  the  smallest  ones,  — -  the 


68  PHYSIOLOGY 

capillaries,  —  whose  walls  are  so  thin  that  when 
the  blood  is  forced  into  them  by  the  beat- 
ing of  the  heart, 
it  oozes  right 
through  the  walls 
and  gives  up  its 
food  to  the  mus- 
cles, nerves,  bones, 
and  skin  that  are 
near. 

People  who  live 
by  a  river  may 
get  the  water 
which  they  use 
and  perhaps  some 
of  their  food  (fish) 
from  the  river. 
At  the  same  time 
the  drain  from  the 
house  may  carry 
the  waste  matter 
from  the  kitchen 
and  bath  room  and 
pour  it  into  the 

FIG.  10.  — ARTERIAL  CIRCULATION.  river.     So  that  the 


THE   BLOOD 


69 


river  serves  the  double  purpose  of  bringing  food 
and  drink  and  of  carrying  away  waste  materials. 
Figure  11  shows  how  the  arteries  distribute  the 
blood  to  the  tissues  through  the  capillaries. 

Each  part  of  the  body  can  take  from  the  blood 
just  such  things  as  feed  it  best.  While  this  is 
being  taken  up,  the 
waste  matter  in  the  tis- 
sues oozes  back  into  the 
capillaries,  and,  with  the 
blood  which  did  not  pass 


through  the  walls,  is  carried  on  in  a  second  set 
of  tubes  —  the  veins,  which  carry  all  the  waste 
that  is  given  off  by  the  body  into  larger  and  still 
larger  pipes  or  veins,  until  it  again  empties  into 
the  heart,  but  this  time  into  the  right  side. 

The  heart  has  two  separate  sides  with  no  door 
between,  and  into  the  left  side  all  the  red,  pure 
blood  flows,  while  all  the  impure  blood  flows  into 


TO 


PHYSIOLOGY 


the  right  side.     From  the  right  side  of  the  heart 
the  blood  is  sent  to  the  lungs. 

Do   you    see   why   the    course   of   the  blood  is 
called    its   circulation  ?      Because   it   starts  from 


FIG.  11.  —  This  shows  how  an  artery  divides  into  small  capillary  branches. 
The  blood  slowly  flows  or  filters  through  the  capillaries  and  then  gath- 
ers into  a  vein  and  flows  away  to  the  heart.  The  lighter  shaded 
bodies  (r)  are  the  red  corpuscles  carrying  oxygen  to  the  tissues.  The 
larger,  darker  bodies  (w)  are  white  corpuscles.  In  one  place  (a)  the 
white  corpuscles  have  gotten  out  of  the  capillary  into  the  tissue  to 
destroy  some  minute  disease  germs  that  might  seriously  injure  the 
body  if  they  were  not  destroyed  by  the  white  corpuscles. 

one  place,  flows  out  to  different  parts,  comes 
back  to  the  same  place,  and  then  goes  over  and 
over  this  same  course.  It  circulates  over  the 
body. 


THE   HEART  BEAT  AND  THE  PULSE  71 

THE   HEART   BEAT   AND   THE   PULSE 

PUT  your  hand  on  your  left  side  and  feel  the 
beating  of  the  heart  as  it  is  pumping  the  blood 
through  the  arteries.  You  could  count  each 
beat  if  you  tried,  and  tell  how  many  times 
the  heart  beats  in  a  minute,  and  could  see  that 
the  heart  beats  at  nearly  the  same  rate  all  the 
time. 

With  the  tips  of  the  fingers  of  one  hand  feel 
the  wrist  of  the  other  hand  and  find  the  beating 
or  throbbing  artery.  The  throbbing  of  the  artery 
is  called  the  pulse.  All  of  the  arteries  pulsate 
or  throb  with  each  beat  of  the  heart.  The  reason 
we  do  not  feel  them  is  that  the  arteries  are 
usually  buried  deep  among  the  muscles  near  to  the 
bone.  Sometimes  an  artery  lies  near  to  the  skin, 
and  then  one  can  feel  it  pulsate.  The  pulsation 
is  caused  by  the  beating  of  the  heart,  and  has, 
of  course,  just  the  same  rate  as  the  heart  beat. 

Such  exercise  as  running  and  jumping,  and 
such  work  as  keeps  the  body  in  motion,  make 
the  heart  beat  faster  and  work  harder.  Exercise 
and  work  make  us  tired  and  we  need  to  rest. 

Sometimes,  when  one  is  frightened,  the  heart 


72  PHYSIOLOGY 

does  not  beat  in  regular  time  or  with  regular 
force.  This  is  very  hard  on  the  heart,  and  should 
be  avoided  if  possible. 


HOW    NARCOTICS    AFFECT    THE    HEART 

Alcoholic  drinks  and  tobacco  may  also  make 
the  heart  beat  too  fast  and  unevenly.  This  gives 
the  heart  too  much  work,  and  makes  it  "  irritable  " 
we  say.  That  is,  it  beats  fast,  then  slow,  and 
fast  again,  instead  of  beating  evenly.  It  is  dan- 
gerous to  have  a  heart  in  this  condition,  for  it  may 
in  a  serious  case  stop  beating  altogether  if  one 
receives  a  fright  or  takes  much  exercise.  Beer 
may  make  fat  collect  about  the  heart  or  in  its 
walls,  and  make  it  too  weak  to  do  its  work 
properly. 

When  we  know  that  the  whole  work  of  the 
body  depends  upon  the  heart,  we  shall  be  very 
careful  to  do  nothing  that  will  weaken  it  or 
make  it  less  able  to  do  its  work. 

When  one  runs  the  heart  beats  fast  and  strong 
in  order  to  pump  enough  blood  to  the  muscles. 
So  you  see  that  when  one  runs  he  exercises  not 
only  the  muscles  of  his  legs  and  hips,  but  also 


THE   HEART   BEAT  AND  THE  PULSE  73 

those  of  his  chest  that  cause  the  lungs  to  fill,  and 
those  in  the  walls  of  the  heart. 

Running  is  good  for  boys  and  girls  because  it 
makes  all  of  their  muscles  strong,  and  because 
it  makes  the  lungs  and  heart  strong. 

It  is  very  important  to  have  a  strong  heart. 
The  games  and  races  which  boys  and  girls  have 
at  school  are  very  important ;  and  every  boy  and 
girl  should  try  to  excel  in  them.  If  one  gets 
a  strong  heart  in  youth  it  may  help  him  to  keep 
well  throughout  life. 

The  principal  work  of  the  white  corpuscles  is 
to  guard  the  body  against  disease.  When  alcohol 
is  taken  into  the  stomach,  it  is  absorbed  into  the 
blood,  where  it  injures  the  white  corpuscles  and 
makes  them  less  able  to  do  their  work.  This 
leaves  the  body  less  able  to  resist  disease. 
Persons  who  use  alcoholic  drinks  are  thus  more 
likely  to  get  sick  than  are  persons  who  do  not 
use  them. 

SOMETHING   TO    FIND    OUT 

Count  the  pulse  of  a  playmate  or  of  yourself, 
and  find  how  many  times  it  beats  each  minute. 

Does  it  make  the  heart  beat  faster  to  run  or  to 
jump  or  to  climb  stairs  ?  If  so,  how  much  ? 


74  PHYSIOLOGY 

Put  your  ear  over  the  place  where  your  play- 
mate's heart  is  beating  and  listen  to  the  heart. 
What  is  it  saying  ? 

Perhaps  the  butcher  will  get  the  heart  of  a 
sheep  or  calf  for  the  class  to  study ;  or,  perhaps, 
a  member  of  the  class  can  bring  the  heart  of  a 
chicken  or  turkey  from  home.  Make  slices  across 
the  heart  from  the  tip  toward  the  base,  until  half 
of  the  heart  is  thus  sliced ;  make  drawings  of  the 
largest  of  these  slices.  How  does  the  left  ventricle 
differ  from  the  right  ?  Now  cut  the  ventricles 
open ;  study  the  valves ;  draw  pictures  of  them. 

HOW   THE   BLOOD   IS   MADE   PURE 

IN  an  earlier  lesson  we  read  that  the  impure 
blood  emptied  into  the  right  side  of  the  heart, 
but  there  we  left  it  without  saying  what  became 
of  it. 

If  this  impure  blood  were  to  go  back  over  the 
body,  it  would  poison  it  and  make  the  person  sick; 
but  before  it  is  used  again  it  is  changed.  We 
must  learn  how  this  change  comes  about. 

Put  your  hand  on  your  chest  and  notice  how 
it  rises  and  falls  all  the  time.  If  you  wish, 


THE  ORGANS   WITH   WHICH  WE  BREATHE      75 

you  can  make  it  rise  and  fall  very  much  or  very 
little,  and  you  can  make  the  pauses  between  the 
motions  long  or  short.  That  is  the  most  that 
you  can  do  with  it,  and  as  soon  as  you  stop 
thinking  about  it,  it  goes  on  again  as  before. 

We  know  how  needful  it  is  to  have  water  and 
food,  but  we  can  do  without  these  longer  than 
without  the  air  which  we  take  in  with  each  rise 
of  the  chest.  In  the  opening  into  which  the  food 
goes  when  swallowed  there  are,  you  remember, 
two  air  passages  besides  the  passage  into  which 
the  food  empties. 

THE   ORGANS   WITH  WHICH  WE   BREATHE 

CLOSE  the  mouth  and  draw  in  the  breath,  and 
you  will  feel  the  air  passing  through  the  nose 
opening.  Be  sure  to  breathe  through  the  nose, 
as  it  will  prevent  particles  of  dust  from  going 
into  the  air  passages,  and  the  air  will  be  warmed 
before  it  reaches  the  delicate  linings  of  the  air 
tubes.  It  passes  the  muscle-curtain  which  is  drawn 
away,  enters  the  large  passage  which  serves  for 
both  food  and  air,  and  when  the  little  door  over 
the  windpipe  is  lifted,  it  enters  the  windpipe. 


76  PHYSIOLOGY 

Feel  the  throat  with  the  fingers,  and  you  will 
find  the  "  Adam's  Apple."  Notice  that  when  you 
swallow,  this  organ  —  the  larynx — moves  quickly 
upward ;  that  brings  its  open  upper  end  close  to 

the  root  of  the 
tongue,  where 
the  epiglottis 
can  keep  food 
or  liquids  from 
going  down  into 
the  windpipe 
(see  Fig.  1). 

Feel  the  throat 
below    the    lar- 


Fia.  12.—  THE  WINDPIPE  AND   ITS  BRANCHES    ynx.        One     Can 
IN  THE  LUNGS. 


L,  the  larynx;  T,  the  trachea;  B,  the  bronchial    easilj     nn(l 

tubes,  whose  small  branches  are  called  bron-     r.^Q.0    of      rrristle 
chicles.    The  little  tufted  sacs  at  the  ends  of 

the  bronchioles  are  the  air  sacs  or  air  cells  of    \\rhich    keep    the 
the  lungs.  —  [TRACY]. 

windpipe  open. 

Look  at  the  picture  (Fig.  12)  and  you  will  see 
this  tube,  —  the  windpipe,  —  and  see  how  it 
branches,  and  branches  again,  into  the  tiny  branches 
which  you  see  at  the  end.  These  tubes  enter  the 
lungs  just  before  they  send  off  the  first  branches, 
and  all  of  the  branching  is  done  within  the  lungs. 


HOW   THE   BLOOD   IS  MADE  PURE  77 

The  lungs  lie  one  in  each  side  of  the  chest,  and 
are  like  two  large  sponges  which  take  up  air  in- 
stead of  water.  They  are  elastic,  like  rubber,  and 
become  larger  when  filled  with  air  and  smaller 
when  emptied. 

The  lungs  are  elastic  because  they  are  composed 
of  many,  many  tiny  air  sacs  which  are  elastic,  and 
expand  and  contract. 

WHAT   TAKES    PLACE   IN   THE   LUNGS 

When  one  draws  a  full  deep  breath,  the  air  goes 
down  the  windpipe,  out  through  all  the  branches, 
into  the  little  sacs  at  the  end  of  each  branch. 

When  the  air  is  breathed  out,  these  little  sacs 
are  emptied,  and  the  air  passes  out  the  way  it 
came  in. 

If  this  were  all  the  air  did,  simply  to  go 
through  the  tubes  into  the  lungs  and  through 
tubes  out  again,  it  would  be  a  great  deal  of 
work  for  nothing;  but  if  the  air  which  goes  into 
the  lungs  and  the  air  which  goes  out  be  examined, 
it  will  be  found  that  a  change  has  taken  place. 
To  understand  this  we  will  go  back  a  little. 

We  left  the  blood  in  the  right  side  of  the 
heart,  but  from  there  it  was  carried  in  tubes  to 


78  PHYSIOLOGY 

the  lungs,  where  the  plasma  of  the  blood  gave 
up  the  impurities  it  had  collected  in  the  different 
parts  of  the  body,  and  took  in  a  new  load  of 
oxygen  to  carry  back  to  the  left  side  of  the  heart. 
It  is  the  red  corpuscles  of  the  blood  that  carry 
the  oxygen  from  the  lungs  to  the  tissues.  From 
the  left  side  of  the  heart  the  blood  is  pumped 
through  the  arteries,  each  corpuscle  bearing  its 
load  of  oxygen  to  the  muscles,  glands,  and 
brain. 

WHY   WE    NEED    PURE   AIR 

We  have  learned  that  the  air  which  goes  into 
the  lungs  carries  the  oxygen  that  keeps  the  blood 
red  and  pure,  and  that  the  air  which  we  breathe 
out  from  the  lungs  contains  less  oxygen,  more 
water,  and  a  gas  which  the  blood  brings  from  the 
tissues  and  gives  up  to  the  lungs.  This  gas  is 
called  carbon  dioxide.  It  is  the  same  kind  of  gas 
as  that  which  is  given  off  from  the  yeast  plant 
when  it  is  causing  fermentation. 

If  the  purity  of  the  blood  depends  upon  the 
oxygen  in  the  air,  you  will  readily  see  that  the 
purer  the  air  the  better  it  is  for  the  body. 

If  the  air  which  has  been  breathed  loses  oxygen 


THE  ORGANS   WITH    WHICH   WE   BREATHE       79 

and  gets  carbon  dioxide,  it  certainly  is  not  fit  to 
be  used  over  and  over  again. 

THE    CARE   OF   THE    LUNGS 

Most  people  do  not  realize  that  they  need  to 
take  any  thought  or  care  of  the  lungs,  but  it  is  just 
as  important  that  they  be  exercised  and  developed 
as  that  the  muscles  be  exercised  and  developed. 

One  should  early  form  the  habit  of  taking  daily 
a  few  minutes  of  deep  breathing  in  the  open  air. 
In  taking  this  exercise  one  should  stand  with  head 
erect  and  shoulders  back,  and  should  draw  in  just 
as  much  air  as  possible.  After  holding  this  air  for 
a  few  seconds,  it  should  be  allowed  to  flow  out 
slowly  and  the  lungs  completely  emptied.  This 
"  forced  respiration  "  should  be  repeated  over  and 
over  again  for  at  least  five  minutes.  If  one  were 
to  do  this  every  morning  and  evening  he  would 
make  his  lungs  so  large  and  strong  that  the  germs 
of  disease  would  probably  never  lodge  in  them. 

Besides  this  forced  respiration  one  needs  to  take 
some  brisk  exercise  like  rapid  walking,  running, 
swimming,  skating,  rowing,  cycling,  or  fast  riding 
on  horseback.  All  of  these  exercises  require  rapid 
and  deep  breathing,  and  all  of  them  develop  the 


80  PHYSIOLOGY 

lungs  and  make  them  strong  enough  to  throw  off 
the  germs  of  consumption  which  we  take  in  with 
the  breath  every  day,  if  we  live  in  a  large  city. 

VENTILATION" 

When  a  room  is  shut  up  tight  and  several 
persons  are  breathing  the  air,  it  is  not  long  before 
there  comes  to  be  so  much  of  the  carbon  dioxide 
and  so  little  of  the  oxygen  that  it  does  not  purify 
the  blood. 

Have  you  not  noticed  how  red  and  hot  the  cheeks 
become,  and  how  the  head  aches  after  sitting  in  a 
room  which  has  not  enough  oxygen?  These  things 
are  only  to  warn  one  that  the  body  has  not  enough 
oxygen,  but  the  real  harm,  that  cannot  be  noticed 
at  once,  is  much  greater  than  this. 

There  should  be  some  way  for  fresh  air  —  that 
is,  out-of-door  air  —  to  enter  the  room  in  which 
one  sits,  works,  or  sleeps.  There  need  not  be  a 
large  opening,  nor  need  it  always  be  in  the  same 
room  which  one  occupies ;  but  it  ought  to  be 
enough  so  that  the  air  is  changing  all  the  time 
without  making  a  draught. 

In  schoolrooms  where  there  are  so  many  people 
breathing  the  air  at  one  time,  there  must  be  some 


THE  ORGANS   WITH   WHICH   WE  BREATHE      81 

special  way  for  the  pure  air  to  come  in  and  the  foul 
air  to  go  out,  or  else  each  pupil  will  breathe  the 
impure  air  thrown  out  as  waste  by  the  others. 

Not  only  is  this  unpleasant,  but  it  poisons  the 
blood  and  makes  the  school  work  very  hard  to  do. 
Pupils  can  do  much  less  brain  work  in  impure  air 
than  in  pure  air. 

Most  of  the  catarrhs,  sore  throats,  and  other 
forms  of  colds  are  contracted  from  the  want  of 
proper  ventilation.  It  is  possible  to  catch  as  bad 
a  cold  in  a  close,  ill-ventilated  room  as  in  a  cold, 
draughty  one.  Pure  air  is  the  surest  preventive 
of  colds,  as  of  many  other  diseases. 

When  exercise  is  taken,  much  more  air  is 
breathed  into  the  lungs,  as  more  air  is  needed. 
We  should  therefore  take  great  care  to  have  this 
air  pure.  There  is  little  danger  of  taking  cold 
while  we  exercise  if  we  go  to  a  warm  place  after 
we  stop  exercising. 

When  you  go  from  the  pure  out-of-door  air  into 
a  room  you  can  tell  very  quickly  whether  the  air 
inside  is  fit  to  breathe.  If  there  is  a  close  or  bad 
smell  about  the  room  it  needs  airing. 

When  one  is  sick,  the  little  white  corpuscles 
need  a  plentiful  supply  of  oxygen  for  carrying  on 

HALL'S  INT.  PHYS. — 6 


82  PHYSIOLOGY 

their  work  of  fighting  the  disease.  The  sick  room, 
therefore,  should  be  always  well  aired.  There 
is  no  danger  of  taking  cold  if  one  is  covered  up 
warmly  and  is  not  in  a  draught.  There  is  always 
danger,  whether  one  is  sick  or  well,  in  breathing 
bad  air. 

In  ordinary  breathing  we  do  not  completely  fill 
the  lungs  with  air.  It  is  a  good  practice  to  take 
frequent,  long,  deep  breaths  of  fresh  air,  filling  the 
lungs  and  holding  it  while  you  count  ten.  This 
enlarges  and  strengthens  the  lungs,  besides  aiding 
in  purifying  the  blood. 

EFFECT  OF  ALCOHOL  AND  TOBACCO  ON  LUNGS 

A  noted  physician  of  Paris  says  that  he  finds 
that  many  of  the  alcohol  patients  discharged  from 
his  hospital  very  soon  come  back  to  be  treated  for 
consumption.  This  is  the  opinion  expressed  by 
many  other  medical  writers.  The  reason  given 
is  that  alcohol  makes  the  body  less  able  to  resist 
the  germs  of  consumption  which  may  be  in  the 
air,  but  which  cannot  get  a  chance  to  begin  their 
work  when  the  body  is  strong  and  in  vigorous 
health. 

Physicians    have    found  that  people   who  use 


THE  ORGANS  WITH  WHICH   WE  BREATHE      83 

alcoholic  drinks  regularly  are  more  likely  to  have 
pneumonia  and  certain  other  lung  diseases  than 
are  people  who  do  not  use  such  drinks  at  all. 
Besides  this,  when  a  drinking  man  gets  pneumonia, 
he  is  likely  to  have  it  more  severely  than  is  the 
total  abstainer  and  is  less  likely  to  recover. 

The  use  of  tobacco  irritates  the  lining  of  the 
throat  and  causes  the  mucus  to  flow  more  freely 
than  is  natural,  and  this  is  likely  to  cause  an 
inflammation  of  the  throat. 

THINGS    TO    FIND    OUT 

How  many  breaths  does  one  naturally  take  in 
one  minute  when  sitting  quietly  ? 

Does  one  breathe  faster  after  running  two  blocks 
or  after  running  up  two  flights  of  stairs  ?  Does 
one  breathe  more  deeply  after  such  exertion  ? 
Why  is  the  breathing  changed  when  one  exercises 
vigorously  ? 

How  does  a  frog  breathe  ? 

How  does  a  bird  breathe  ? 

How  does  a  fish  breathe  ? 

How  does  a  crayfish  (crab)  breathe  ? 

Does  a  plant  breathe?  If  so,  what  does  the 
plant  have  that  corresponds  to  our  lungs  ? 


84  PHYSIOLOGY 

THE   WASTE   MATTER   OF   THE   BODY   AND 
HOW   IT    IS   THROWN   OFF 

IN  the  town  which  we  visited,  all  water  that 
was  used  was  carried  off  in  pipes  and  thrown 
away.  To  be  sure,  it  went  into  streams  of  water 
which  finally  carried  it  to  the  sea,  from  which 
it  was  in  time  evaporated  by  the  sun,  floated 
away  in  clouds,  and  was  brought  back  as  pure 
rain  water  for  use  again. 

In  the  body  we  have  seen  that  the  blood  cir- 
culates over  and  over  again,  being  made  pure  in 
the  lungs  and  used  over  again  in  the  same  body. 

There  is  a  good  deal  of  waste,  however,  that 
has  to  be  thrown  out  of  the  body.  The  undi- 
gested food,  which  never  becomes  a  part  of  the 
body,  is  carried  along  the  large  intestine  until 
it  is  expelled.  This  waste  material  should  be 
expelled  every  day,  as  some  of  the  unclean  mat- 
ter from  it  will  soak  through  the  walls  of  the 
intestine  if  it  stays  there  long,  and  will  be  taken 
up  into  the  blood  and  poison  it.  People  some- 
times have  fever  from  this  poison. 

The  special  organs  for  sending  out  the  waste 
are  the  kidneys.  The  kidneys  of  a  person  are 


THE  WASTE  MATTER  OF  THE  BODY     85 

bean-shaped  organs  that  are  just  about  long 
enough  to  cross  the  palin  of  the  hand.  They  lie 
in  the  abdomen  back  of  the  intestines,  and  next 
to  the  small  of  the  back.  Large  blood  vessels 
carry  blood  to  the  kidneys  to  be  purified,  and 
other  large  vessels  carry  it  back  to  the  veins  in 
which  it  returns  to  the  heart. 

These  organs  have  the  power  to  separate  the 
waste  water  and  other  waste  matter  from  the 
blood.  Some  of  these  waste  materials  would 
poison  the  body  if  they  were  not  cast  out. 
When  too  much  of  our  food  is  meat  or  when 
one  overeats  of  any  kind  of  food,  the  kidneys 
have  too  much  work  to  do  and  may  become 
diseased. 

We  can  help  keep  the  kidneys  in  good  order 
by  eating  moderately  and  by  drinking  plenty  of 
fresh,  pure  water.  It  relieves  the  kidneys  if  one 
flushes  the  system  sometimes  by  drinking  a  great 
deal  of  water.  Lemonade  also  helps  the  kidneys 
to  throw  off  waste  matter. 

Of  the  work  which  the  lungs  do  in  casting 
out  waste  we  have  already  spoken,  and  of  other- 
organs  whose  work  is  in  part  that  of  carrying  out 
the  body  waste  we  shall  speak  in  the  next  lesson. 


86  PHYSIOLOGY 

THE   SKIN   AND   ITS   WORK 

THE  first  use  of  the  skin  is  to  protect  the 
body.  It  covers  the  muscles  and  keeps  them 
from  being  bruised  or  torn. 

The  skin  is  composed  of  two  layers,  an  outer 
thin  layer  which  has  no  blood  vessels  and  few 
nerves,  and  an  inner  layer  which  has  many  blood 
vessels  and  nerves.  In  the  outer  layer  is  the 
coloring  matter  which  gives  a  person  a  dark  or 
light  skin.  This  layer  seems  when  touched  to 
have  feeling,  but  that  is-  caused  by  the  outer 
layer  pressing  upon  the  nerves  of  the  inner 
layer. 

Over  most  of  the  body  the  outer  layer  of  the 
skin  is  very  thin,  not  thicker  than  paper;  but 
over  the  palms  of  the  hands  and  the  soles  of 
the  feet  —  places  which  come  in  contact  with 
hard  and  rough  substances  —  the  outer  layer 
or  cuticle  is  very  thick  and  tough. 

The  outer  layer  of  the  skin  tends  to  thicken 
when  it  is  rubbed  or  pressed  for  a  long  time  in 
the  same  place.  This  is  the  cause  of  the  cal- 
louses that  sometimes  come  on  the  inside  of  the 
hand. 


THE  SKIN  AND  ITS  WORK  87 

The  lips  and  the  inside  of  the  body  are  covered 
by  skin  of  a  little  different  kind.  This  is  thinner 
and  gives  out  a  fluid  which  always  keeps  it  moist. 

The  corns  that  form  on  some  people's  feet 
are  caused  by  the  rubbing  or  by  the  pressure  of 
the  shoes.  Shoes  should  not  be  too  tight  or  too 
loose.  If  they  are  of  soft  leather  and  fit  the 
feet  snugly  but  not  tightly,  there  should  be  no 
corns  upon  the  feet. 

The  skin  has  another  very  important  work. 
Look  at  the  palm  of  your  hand  and  you  can 
see  the  tiny  lines  or  ridges  running  all  over  the 
hand.  If  your  eyes  were  sharp  enough,  or  if 
you  had  a  magnifying  glass,  you  might  see  on 
the  ridges  many  little  dark  spots. 

The  spots  seen  in  the  skin  are  really  tiny 
openings.  Each  opening  is  the  mouth  of  a  small 
tube  or  pipe  (see  Fig.  13).  This  is  a  sweat 
tube,  and  it  runs  down  through  both  layers  of 
the  skin.  Just  below  the  under  layer  it  forms 
a  coil.  This  coil  is  the  sweat  gland,  which  col- 
lects the  sweat  or  perspiration  from  the  blood. 

The  sweat  which  collects  in  these  little  coils 
passes  through  the  tubes,  and  on  a  warm  day 
you  can  see  it  standing  in  drops  on  the  skin. 


88 


PHYSIOLOGY 


If  there  is  much  of  it,  it  runs  off,  but  when  less 
it  dries  up. 

One  perspires  all  of   the  time,  whether  it  can 


FIG.  13. — THE  SKIN  SHOWING  THE  UPPER  LAYER  AND  THE 

LOWER  LAYER. 

h,  the  sweat  tube.  g,  the  sweat  gland.  i,  sweat  pore. 

k,  the  hair  tube.  o,  the  oil  gland. 

be  seen  or  not.     Indeed,  nearly  a  quart  of  waste 
water  goes  off  in  this  way  each  day. 

It  is  only  the-  water  part  of  the  waste  that 
dries  up,  and  the  rest  stays  on  the  skin  until  it 
is  washed  off.  That  is  why  our  bodies  become 
unclean,  even  where  covered  with  clothing. 


THE   SKIN   AND   ITS    WORK  89 

To  get  rid  of  this  waste  that  it  may  not  fill 
up  the  sweat  tubes  so  that  the.  sweat  cannot 
get  out,  we  need  to  give  the  body  a  thorough 
washing  with  warm  water  and  soap  at  least 
once  a  week. 

Besides  the  sweat  glands  of  the  skin,  there 
are  other  glands  which  make  oil.  They  pour 
out  this  oil  to  keep  the  skin  soft.  Dark  skins 
seem  to  have  more  of  this  oil  than  fair  skins, 
and  sometimes  it  is  necessary  for  fair  people  to 
add  a  little  oil  to  the  skin  after  a  bath  to  keep 
it  from  getting  rough  or  sore. 

HOW   ALCOHOL   AFFECTS   THE    SKIN 

Persons  who  use  alcoholic  drinks  freely  are 
likely  to  get  very  red  faces.  This  is  because 
the  little  capillaries  or  blood  vessels  of  the  skin 
are  weakened  so  that  the  blood  which  is  being 
forced  through  them  by  the  heart  pushes  their 
walls  out  and  makes  them  much  wider,  so  that 
the  skin  contains  much  more  blood  than  usual, 
and  that  is  what  makes  it  look  red. 

If  one  takes  these  alcoholic  drinks  only  a  few 
times,  the  skin  recovers ;  but  if  their  use  is  con- 
tinued for  many  months  or  years,  the  little  blood 


90  PHYSIOLOGY 

vessels  finally  get  so  weakened  that  they  cannot 
recover  after  each  use  of  the  alcohol,  and  so 
remain  permanently  enlarged. 

THE    HAIR    AND    THE    NAILS 

THE  hair,  the  nails,  and  the  teeth  look  so  dif- 
ferent from  the  skin  that  we  do  not  think  of 
them  as  being  the  same,  and  yet  they  are  formed 
of  the  same  material,  and  all  but  the  teeth  are 
a  part  of  the  body  protection. 

The  nails  give  firmness  and  strength  to  the 
ends  of  the  fingers  and  toes,  and  help  in  picking 
up  things.  They  are  continually  growing,  and 
should  be  kept  trimmed  with  a  sharp  knife  or 
scissors,  but  never  by  biting  or  breaking.  It  is 
so  easy  for  dirt  to  get  under  the  nails  that  they 
need  careful  cleaning  each  day. 

When  we  speak  of  the  hair  we  usually  mean 
the  hair  on  the  head,  but,  in  fact,  there  is  hair 
all  over  the  body  except  on  the  palms  of  the 
hands  and  the  soles  of  the  feet. 

Hold  your  hand  to  the  light  and  look  across  the 
back  of  it.  Do  you  see  the  little  short  hairs  ? 
There  are  just  such  hairs  over  most  of  the  body. 


THE   HAIR  AND  THE  NAILS  91 

Look  at  the  picture  (Fig.  13)  and  see  how  the 
root  of  the  hair  runs  down  through  the  upper 
layer  of  the  skin,  and  how  the  oil  gland  empties 
at  the  base  of  the  hair.  The  oil  not  only  keeps 
the  skin  smooth,  but  it  keeps  the  hair  oiled. 
When  the  hair  is  well  brushed,  it  causes  the  oil 
to  flow  and  make  the  hair  look  glossy. 

Dark  hair  is  likely  to  be  much  more  oily  than 
light  hair  because  the  oil  glands  work  more  in 
dark-skinned  people. 

Brushing  helps  to  keep  the  hair  clean  by 
removing  the  dust;  but  the  hair  should  be 
washed  often  enough  to  take  away  the  col- 
lected oil  and  give  a  chance  for  the  fresh  oil 
to  flow. 

It  is  possible  to  wash  the  hair  too  much,  but 
that  very  seldom  happens. 

Girls  who  have  long,  heavy  hair  often  dread 
to  have  it  combed.  But  they  need  not  if  it  is 
properly  done.  Starting  the  comb  from  the 
head  and  dragging  it  down  to  the  end  of  the 
hair  without  regard  to  snarls  and  tangles  is  not 
the  best  way  to  take  care  of  the  hair,  and  this 
kind  of  combing  is,  of  course,  painful ;  but  if  the 
hair  is  held  in  the  hand,  the  comb  is  started  at 


92  PHYSIOLOGY 

the  ends  of  the  hair,  and  the  snarls  worked  out 
little  by  little  from  the  ends  up  toward  the  head, 
there  will  be  no  pulling,  no  pain,  and  no  dam- 
age to  the  hair. 

The  small  hairs  that  cover  the  body  do  not 
come  straight  out  from  the  skin,  but  slanting, 
and  all  those  that  are  near  together  lie  in  the 
same  direction. 

When  the  skin  is  warm  the  hair  lies  down. 
When  cold  strikes  the  skin  these  hairs  all  rise 
and  stand  up  straight.  This  rising  of  the  hair 
pushes  up  a  bit  of  skin  around  each  hair,  and 
makes  what  we  call  "goose  flesh." 

Sometimes  in  fright  the  hair  of  the  head  rises 
in  this  way,  and  we  say,  "  The  hair  stood  on 
end." 

THINGS    TO    FIND    OUT 

Did  you  ever  see  the  hairy  coat  of  a  horse  or 
cow  lose  its  glossy  smoothness  when  the  animal 
is  led  out  of  a  warm  barn  on  a  cold  winter  day? 
What  has  happened  and  why  has  it  happened  ? 

Did  you  ever  notice  that  when  a  dog  is  angry 
the  hair  upon  his  neck  will  rise  ?  Why  does 
nature  provide  for  a  dog  in  this  way  ? 

Did  you  ever  see  the  hair  upon  a  kitten's  back 


BATHING  93 

and  tail  rise?     If  so,  under  what  circumstances? 
Why  are  they  provided  by  nature  in  this  way? 


Why  do  we  have  "  goose  flesh  "  when  the  skin 
becomes  suddenly  chilled  ?  Is  this  a  provision  of 
nature  ?  If  so,  what  is  its  purpose  ? 


BATHING 

HAVING  seen  how  much  our  health  depends 
upon  our  bodies  being  clean,  we  will  talk  about 
some  of  the  ways  of  keeping  it  so. 

As  the  face,  ears,  neck,  and  hands  are  not 
covered,  they  collect  much  that  is  unclean  from 


94  PHYSIOLOGY 

the  air,  and  must  be  washed  more  often  than 
the  rest  of  the  body.  But  the  skin  of  the  entire 
body,  as  we  have  seen,  collects  uncleanness  from 
within  which  must  be  washed  away. 

For  simple  cleanliness  a  warm  bath  with  soap 
once  or  twice  a  week  is  enough,  especially  if  the 
skin  is  rubbed  hard  enough  to  take  away  the 
dead  scales  of  the  skin,  and  the  oil  with  the  dust 
which  sticks  to  it. 

There  are  other  uses  of  the  bath  besides  that 
of  cleanliness ;  one  very  important  one  is  lowering 
or  raising  the  temperature  of  the  body. 

If  every  morning  before  dressing  one  should 
wash  the  entire  body  with  cold  water,  uncover- 
ing, bathing,  and  rubbing  only  a  portion  of  the 
body  at  a  time,  it  would  make  the  person  much 
less  liable  to  take  cold. 

After  a  sponge  bath  of  this  kind,  a  good  hard 
rubbing  should  be  given  the  skin  so  that  it  is 
left  warm  and  glowing.  Washing  with  warm 
water  in  the  morning  for  cleanliness  should 
always  be  followed  by  a  dash  of  cold  water  to 
prevent  taking  cold.  Every  bath  should  be  fol- 
lowed by  rubbing  with  a  coarse  towel  until  the 
skin  is  red  and  glowing. 


BATHING  95 

In  summer  time,  when  the  body  gets  heated 
and  one  perspires  much,  it  is  both  cooling  and 
restful  to  take  a  sponge  bath  at  night,  using  cool 
water,  which  gives  one  a  refreshed  and  rested 
feeling.  , 

Although  baths  are  so  needful  for  cleanliness 
and  health,  they  must  be  taken  at  the  proper 
time  in  order  to  do  the  most  good  and  in  some 
cases  to  keep  from  doing  harm. 

For  an  hour  after  eating  the  stomach  needs 
an  extra  amount  of  blood  to  digest  the  food. 
If  a  bath  is  taken  during  this  time  it  draws  a 
large  portion  of  the  blood  to  the  skin,  and  the 
stomach,  for  want  of  it,  cannot  so  readily  digest 
the  food.  It  is  bad  also  to  draw  the  blood  from 
the  stomach  just  before  a  meal.  It  is  better, 
then,  not  to  bathe  just  before  or  just  after  a 
meal ;  and,  as  bathing  opens  the  sweat  tubes  and 
makes  the  skin  more  sensitive  to  cold,  it  is 
better  not  to  go  out  of  doors  directly  after  a 
bath.  Exercise  raises  the  body  temperature,  and 
a  bath  taken  just  after  violent  exercise  or  at 
any  time  when  one  is  overheated  is  likely  to 
give  a  shock  and  make  one  ill. 

In  summer,  when  one  can  bathe  in  the  river, 


96 


PHYSIOLOGY 


lake,  or  sea,  the  same  general  rules  should  be 
followed,  and  care  must  also  be  taken  that  the 
pleasure  in  bathing  does  not  lead  one  to  remain 
too  long  in  the  water. 


BATHING  BEACH,  COTTAGE  CITY,  MARTHA'S  VINEYARD. 

Even  though  the  water  is  warm,  the  out-of- 
door  bath  should  not  last  more  than  twenty  or 
thirty  minutes,  and  for  many  people  fifteen 
minutes  will  be  found  quite  long  enough. 


CLEANLINESS  AND   HEALTH  97 

CLEANLINESS  AND  HEALTH 

WHILE  we  are  talking  about  the  bathing  of 
the  body  for  cleanliness,  we  may  as  well  talk 
about  cleanliness  in  general,  because  it  is  quite 
as  important  to  keep  the  house  with  the  kitchen 
and  dining  room  utensils  and  dishes  clean  as  it 
is  to  keep  the  body  clean. 

People  who  keep  their  bodies  clean  are  quite 
sure  to  keep  their  clothing  and  their  house 
clean. 

Clothing  which  is  worn  next  to  the  skin  takes 
up  impurities  which  are  thrown  out  of  the 
body,  and  must  be  thoroughly  washed  in  hot 
water  and  soap  at  least  once  each  week,  and 
oftener  in  summer.  When  washed  clothing  is 
drying  it  should  hang  in  the  open  air;  for  noth- 
ing except  the  pure  out-of-door  air  can  give  to 
clothes  the  sweet,  clean  smell  that  every  one 
enjoys. 

Bedding  should  be  aired  daily  and  washed  as 
often  as  once  each  week.  This  seems  an  un- 
necessary rule  of  housekeeping  to  give  to 
American  youth ;  but  there  are  many  foreign 
countries  where  the  bedding  is  washed  not 

HALL'S  INT.  PHYS.  — 7 


98  PHYSIOLOGY 

oftener  than  once  in  a  month,  or  even  once  in 
three  months. 

Cleanliness  in  the  kitchen  and  dining  room 
is  also  important.  When  the  table  is  immacu- 
late, the  dishes  shining  with  cleanliness ;  when 
the  kitchen  floor,  table,  and  sink  are  spotless ; 
when  the  utensils  shine,  there  is  not  much 
opportunity  for  the  germs  of  disease  to  remain 
in  the  house  even  if  they  are  brought  in  acci- 
dentally. The  refrigerator  must  also  be  cleaned 
and  aired  once  each  week,  and  the  cellar  or 
basement  must  be  clean  and  well  aired. 

Houses  that  are  kept  in  this  way  are  healthy 
places  for  children  to  grow  up  in. 

Schoolhouses  and  other  public  buildings  must 
also  be  kept  clean.  People  who  occupy  public 
buildings  are  under  obligations  to  the  community 
at  large  to  keep  the  buildings  as  clean  and  neat 
as  possible. 

Books  in  school  libraries  and  in  public  libra- 
ries should  be  handled  by  clean  hands  only,  so 
that  these  books  may  remain  clean  even  though 
they  may  be  in  constant  use  for  months.  If 
one  must  use  a  soiled  book  from  a  public  library 
he  will  be  wise  to  wash  his  hands  afterward. 


HOW  THE  BODY  IS  WARMED  99 

ALCOHOL   AND   BATHING 

It  is  thought  by  some  that  a  drink  of  whisky 
after  taking  a  bath  will  prevent  one  from  taking 
cold.  If  you  have  understood  what  has  been  said 
before  about  the  effect  of  alcohol  upon  the  skin 
and  its  effect  on  the  warmth  of  the  body,  you  can 
now  see  that,  if  alcohol  makes  the  blood  come  to 
the  skin,  it  will  lose  some  of  its  warmth,  and 
though  the  skin  feels  warm  and  comfortable  at 
first  the  body  gets  chilled  later  and  one  is  more 
likely  to  take  cold.  Nature's  method  of  making 
the  skin  glow  by  vigorous  rubbing  is  the  only 
safe  way.  People  who  take  cool  or  cold  morning 
baths  followed  by  rubbing  until  the  skin  is  red 
and  glowing  very  seldom  take  cold. 

HOW  THE   BODY  IS  WARMED 

CLOTHING  is  worn,  especially  in  cold  weather, 
to  keep  the  body  warm.  Can  it  do  more  than  that, 
can  it  make  the  body  warm  ? 

Try  wrapping  up  a  piece  of  iron  or  wood  in  a 
shawl ;  will  it  become  warm  ?  Does  a  doll  become 
warm  because  of  its  clothing  ? 

Clothing  adds  nothing  of  warmth  to  the  body, 


100  PHYSIOLOGY 

it  simply  keeps  the  warmth  which  the  body 
already  has  from  leaving.  The  more  clothing 
we  wear  the  warmer  we  become  because  the  less 
heat  escapes. 

Where  then  does  the  body  get  the  heat  which 
the  clothes  keep  in  ? 

Under  the  subject  of  foods  we  learned  that 
part  of  what  we  eat  is  used  for  heating  the  body, 
and  that  starch  food,  sugars,  and  fats  are  the 
greatest  heat  makers. 

To  understand  just  how  this  is  done  is  not 
easy. 

You  have  seen  an  engineer  put  coal  on  a  fire, 
you  have  seen  that  the  fire  makes  the  engine  go, 
and  perhaps  you  have  felt  the  heat  from  the  fire. 
If  the  fire  box  were  shut  up  tight  so  that  no  air 
could  get  in,  the  engineer  might  put  ever  so 
much  coal  on  but  the  engine  would  not  go  and 
you  would  feel  no  heat ;  indeed,  the  fire  would  go 
out. 

It  is  the  oxygen  from  the  air  that  makes  the 
coal  burn  and  give  out  heat,  and  that  is  why  there 
are  drafts  in  all  stoves  and  furnaces.  These 
drafts  provide  a  way  to  let  much  or  little  oxygen 
reach  the  fire  according  as  we  want  much  or  little 


HOW  THE  BODY  IS  WARMED  ;  101 

fire.  Even  when  we  shut  the  stove  or,  furnace 
as  tight  as  we  can,  enough  air  can  get'  nr  through 
the  cracks  to  keep  the  fire  burning  for  a  time. 

The  oxygen  which  we  breathe  makes  the  food, 
which  is  body  fuel,  give  out  heat,  and  enables  us 
to  move.  The  oxygen  and  the  coal  burning  in 
the  engine  give  out  heat  and  enable  it  to  move. 

When  the  fuel  of  the  engine  is  used  up  there 
are  smoke  and  ashes  left,  and  when  the  fuel  of 
the  body  is  used  up  there  is  waste  that  corre- 
sponds to  the  smoke  and  ashes. 

The  undigested  food  which  the  intestine  carries 
off  is  like  the  ashes,  and  the  waste  carried  off  by 
the  skin,  the  lungs,  and  the  kidneys  is  like  the 
smoke. 

Now  we  know  how  the  body  is  made  warm,  let 
us  see  how  nature  planned  to  keep  it  warm. 

To  the  skin  has  been  given  a  part  of  the  work 
of  regulating  the  heat  of  the  body. 

If  one  becomes  too  warm,  the  sweat  pours  out 
of  the  sweat  tubes  and  the  water  passing  into  the 
air  cools  the  body.  The  reason  we  feel  so  much 
warmer  on  a  moist  hot  day  than  on  a  dry  day  is 
that  this  moisture  cannot  go  out  into  the  air. 

We  can,  in  a  measure,  regulate   our  tempera- 


102  PHYSIOLOGY 

ture  by  food,  clothing,  and  exercise.  A  rapid  use 
of  tHe  muscles  warms  the  body.  Running,  jump- 
ing, or  any  play  or  work  that  makes  the  muscles 
active  are  good  ways  of  warming  the  body. 

The  hair  which  covers  the  head  keeps  it  from 
feeling  every  little  change  of  temperature.  In 
lower  animals  the  temperature  is  partly  regulated 
by  the  hair  which  covers  the  body.  When  it 
rises  and  looks  rough  it  makes  a  thicker,  warmer 
coat  than  when  it  lies  smooth  and  glossy  close  to 
the  animal's  skin.  This  is  the  way  a  horse,  or 
cow,  or  dog,  or  cat  puts  on  an  overcoat. 

It  used  to  be  thought  that  a  drink  of  some 
alcoholic  beverage  would  "  warm  one  up  "  on  a 
cold  day.  What  it  really  does  is  to  make  the 
blood  come  to  the  skin.  That  is  warmed,  and 
the  person  thinks  at  first  that  the  alcohol  has 
warmed  him ;  but  the  body  loses  heat  so  rapidly 
that  it  soon  becomes  chilled  and  much  colder 
than  it  would  have  been  without  the  alcohol. 
Many  men  have  lost  their  lives  by  taking  whisky 
to  keep  them  warm  on  a  cold  day.  Men  who 
travel  in  arctic  lands  avoid  alcohol  because  they 
know  its  dangers.  Some  people  take  alcohol  to 
make  them  cool  in  hot  weather.  It  may  perhaps 


SEEING 


103 


make  them  cooler  at  first;  but  men  who  use 
alcohol  are  much  more  likely  to  get  sunstroke 
than  are  men  who  are  total  abstainers. 


SEEING 

How  many  beautiful  things  there  are  in  the 
world.  I  wonder  if  you  really  know  how  beauti- 
ful and  wonderful  they 
are.  Sometimes  we  grow 
so  used  to  nature's  beauties 
that  we  do  not  see  their 
beauty. 

Think  of  the  sky  with 
its  countless  stars,  the  trees 
with  their  bright  foliage, 
the  flowers  that  grow  at 
our  feet. 

How  much  of  pleasure 
lies  in  beauty,  yet  all  this 
would  be  lost  to  us  without 
the  sense  of  sight. 

Think,  too,  how  many  things  you  do  which 
depend  upon  your  seeing  well,  and  then  you  will 
realize  how  valuable  this  sense  is. 


104 


PHYSIOLOGY 


Look  about  and  see  how  much  there  is  that  is 
beautiful  and  how  much  there  is  to  see.  After 
looking  at  .an  object  you  can  shut  your  eyes  and 
can  still  see  it  with  your  mind. 

If  you  had  never  had  eyes,  you  could  not  bring 
pictures  to  mind  as  you  now  can.  You  could  tell 


FIG.  14.  —  SECTION  OF  THE  EYE. 

a,  bony  case  of  the  eye ;  b,  muscle  to  move  the  eye ;  c  and  d,  coverings  of 
the  eye ;  e,  lining  or  seeing  part  of  the  eye ;  /,  eyelid ;  g,  colored  cur- 
tain or  iris ;  h,  and  i,  clear  windows  of  the  eye. 

the  shape  of  objects  by  feeling  them,  but  without 
sight  all  sense  of  color  would  be  lacking. 

The  eye,  itself,  is  the  shape  of  a  sphere  (Fig. 
14),  and  rests  on  a  cushion  of  fat  in  a  bony  hol- 
low or  socket.  The  upper  edge  of  the  socket 
stands  out  and  forms  the  brow  which  protects 


SEEING  105 

the  eye.  The  skin  over  the  brow  has  a  line  of 
hair  —  the  eyebrow  —  which  keeps  the  perspira- 
tion from  running  into  the  eye. 

Besides  the   brow,  the   eye   is   protected   by  a 
pair   of   fringed    curtains   or   lids   which   can   be 
drawn  over  the  eye  to  shut   out  the  light  when 
one    wishes,    or    to 
cover  the  eye  when 
danger  is  near.    The 
lashes  help  to   keep 
dust  out  of  the  eye. 
If  one  looks  at  the 
eye  (Fig.  15),  he  will 
see  a  round  colored 
part   with    a    black 

FIG.  15.  — THE  HUMAJK  EYE. 

spot  in  the  middle. 

This  colored  part,  which  is  blue  in  some  eyes,  and 
gray,  black,  or  brown  in  others,  is  a  curtain,  and 
the  black  spot  is  a  hole  through  this  curtain.  The 
curtain  is  called  the  iris. 

That  dark  spot  which  you  see  in  the  eye  is 
an  opening  into  a  dark  hole,  and  through  that 
opening  the  light  passes  to  the  inside  of  the  eye. 
The  dark  opening  is  called  the  pupil. 

This   opening    can   be    made    large   or    small. 


106  PHYSIOLOGY 

When  one  looks  at  a  bright  light  or  at  a  very 
near  object,  it  grows  smaller ;  and  when  one  goes 
into  a  dark  place,  it  opens  as  wide  as  it  can  to 
let  in  all  the  light  there  is. 

In  the  section  you  can  see  this  opening  and 
also  see  that  over  it  is  an  outer  covering  (Fig. 
14,  i).  This  covering  is  as  clear  as  glass.  At  the 
back  of  the  eye  may  be  seen  the  nerve  which 
carries  the  messages  to  the  brain  (Fig.  14,  &). 

Without  this  nerve  we  could  really  see  noth- 
ing, for,  although  the  picture  might  be  taken  by 
the  eye,  we  could  not  see  it  unless  the  brain 
could  get  the  message. 

So  much  of  our  knowledge  and  our  happiness 
depends  upon  our  sight  that  we  should  value  and 
take  the  greatest  care  of  our  eyes.  It  does  not 
pay  to  read  when  there  is  not  a  good  light,  and 
to  overwork  the  eyes,  for  the  sake  of  a  little 
pleasure  just  at  the  time. 

In  reading  by  lamplight,  care  should  be  taken 
to  sit  with  the  back  to  the  light  or  to  hold  the 
book  so  that  the  light  is  not  reflected  from  the 
page  directly  into  the  eyes.  Never  read  while 
lying  down. 

Some    eyes   are    nearsighted,  that  is,  they  can 


SEEING  107 

see  only  near  objects  clearly ;  and  some  are  far- 
sighted,  that  is,  they  can  see  far  away  .objects 
with  less  effort  than  they  can  see  near  ones. 

Children  who  have  defects  of  the  eyes  should 
wear  spectacles,  for,  if  they  do  not,  they  may 
have  headache  and  become  irritable,  and  make 
the  eyes  still  worse  by  trying  to  make  them  do, 
alone,  work  for  which  they  need  the  help  of 
glasses. 

To  look  directly  at  the  sun  or  any  bright  light 
hurts  the  eyes,  and  if  done  too  often  or  too  long 
may  seriously  injure  them. 

Several  forms  of  eye  trouble,  commonly 
called  "  sore  eyes,"  come  from  uncleanliness,  and 
are  "  contagious  "  or  "  catching."  For  this  reason 
it  is  never  safe  to  wash  in  a  public  washbasin 
or  to  wipe  on  a  towel  that  others  have  used. 
It  is  better  for  every  pupil  in  school  to  have 
his  own  towel. 

One  should  never  touch  the  eyes  with  fingers 
that  are  not  absolutely  clean.  Earth  soil  has  been 
known  to  cause  serious  eye  trouble.  Catarrh,  and 
straining  the  eye,  as  for  instance  going  without 
glasses  when  the  eye  needs  their  aid,  sometimes 
cause  painful  swellings  on  the  eyelid. 


108  PHYSIOLOGY 

Diseases  of  the  eye  are  also  sometimes  caused 
by  overwork,  poor  or  insufficient  food,  cough, 
strain,  or  the  use  of  alcoholic  liquors.  Alcohol 
and  tobacco  cause  dimness  of  vision. 

The  use  of  tobacco  may  seriously  injure  the 
sight. 

THINGS    TO    FIND    OUT 

Watch  the  pupil  of  the  eye  of  a  person  who 
sits  facing  a  window.  Shade  his  eyes  and  then 
suddenly  withdraw  the  shade  or  let  him  close 
them  and  suddenly  open  them.  Does  the  pupil 
change  in  size  ?  If  so,  what  is  the  change  ? 

Look  at  a  dog's  eyes.  What  is  the  shape  of 
his  pupils? 

What  is  the  shape  of  the  pupil  of  a  cat's  eye  ? 
Of  a  horse's  eye? 

Why  do  the  eyes  of  a  cat  look  so  fiery  red  in 
the  dark? 

How  is  it  that  an  owl  can  see  when  it  is  too 
dark  for  a  person  to  see  ? 

Why  does  the  bright  sunlight  hurt  the  eyes 
of  an  owl  ? 

Can  a  cat,  or  dog,  or  horse  see  better  in  the 
dark  than  a  person  can  ?  If  so,  why  ? 


HEARING  109 

HEARING 

THE  ear,  which  is  the  organ  of  hearing,  is  as 
wonderful  as  the  eye  in  its  structure. 

That  which  we  see  on  the  outside  is  not  the 
hearing  part  of  the  structure,  it  only  catches 
the  sound.  But  quite  out  of  sight  and  reach 
there  is  a  delicate  set  of  bones  •  and  canals  for 
taking  the  sound  to  the  nerve  of  hearing. 

Just  as  the  eye  cannot  carry  a  picture  to  the 
brain  without  the  nerves  of  sight,  so  with  ever 
so  good  an  ear  one  can  hear  nothing  without 
the  nerves  of  hearing. 

In  Figure  16  you  can  see  how  the  air  enters 
the  ear,  and  can  see  where  it  strikes  the  mem- 
brane of  the  ear  drum.  Back  of  the  drum  are 
the  coiled  bony  canals  through  which  the  sound 
is  carried  to  the  nerves. 

The  opening  into  the  ear  is  guarded  from 
insects  by  wax.  Sometimes  too  much  wax 
gathers  in  the  ear,  and  keeps  one  from  hearing 
so  well,  but  it  must  never  be  dug  out  with  any- 
thing smaller  than  the  finger.  A  sharp-pointed 
thing  entering  the  ear  may  do  great  damage.  It 
is  safe  to  say,  never  put  anything  into  the  ear. 


110 


PHYSIOLOGY 


One  should  always  protect  the  ears  against  a 
strong  wind  blowing  into  them  when  riding, 
and  should  not  sit  with  the  ear  exposed  to  a 
draught  of  air  from  open  doors  or  windows. 


FIG.  16.  —  DIAGRAM  OF  THE  PARTS  OF  THE  EAR. 

1,  the  outside  lobe ;  2,  the  outer  opening ;  3,  the  ear  drum ;  4,  tube  leading 
to  the  throat ;  5,  the  coiled  bony  canals. 

Earache  in  children  is  sometimes  caused  by 
sleeping  where  the  head  is  in  a  draught  of  wind 
that  blows  into  the  ears. 

A  blow  upon  the  ear  struck  sometimes  in 
sport  has  injured  the  ear  and  caused  deafness. 
Very  loud  noises  close  to  the  ear,  like  the  report 
of  cannon,  gun,  or  pistol,  or  locomotive  whistles, 
are  sometimes  a  cause  of  deafness.  No  one  in 


HEARING  111 

play  should  strike  another  on  the  ear  or  make 
a  loud  noice  close  to  the  ear.  A  moment's 
sport  may  by  such  means  cause  a  lifelong  loss 
of  hearing.  Tinsmiths,  blacksmiths,  and  other 
workmen  who  are  subject  to  continued  loud 
noises  sometimes  lose  their  hearing  as  a  result. 
The  frequent  use  of  the  telephone,  if  the  re- 
ceiver is  pressed  close  to  the  ear,  may  cause 
ear  trouble. 

Not  only  the  ear,  but  the  nervous  system  is 
affected  unpleasantly  by  too  much  noise.  When 
people  are  very  ill  the  physician  orders  the  sick 
room  to  be  kept  very  quiet,  because  noises  make 
it  harder  for  the  patient  to  get  well.  But  even 
well  people  are  better  off  without  noise.  The 
rattling  of  carts  and  horses'  hoofs  over  cobble- 
stones, the  whiz  and  whir  and  loud  bells  of 
the  street  cars,  the  cries  of  hucksters,  the 
shrieks  of  whistles,  all  strike  upon  the  brain 
through  the  ear,  and  have  an  effect  similar  to 
that  of  a  sudden  bright  light  before  the  eyes. 
When  one  is  fresh  in  the  morning  he  may  not 
notice  these  sounds,  but  they  help  to  tire  him 
almost  as  much  as  his  work,  and  when  he  is  tired 
or  not  feeling  well  they  are  doubly  irritating. 


112  PHYSIOLOGY 

Some  of  these  noises  cannot  be  prevented;  but 
many  of  them  could  be  greatly  lessened  if  peo- 
ple would  only  give  the  matter  a  little  thought. 
Cobblestones  could  give  place  to  asphalt  pave- 
ments, iron  wagon  tires  and  iron  horseshoes  to 
rubber  tires  and  rubber  horseshoes.  Many  loud 
bells  could  be  dispensed  with,  and  the  signals 
could  be  given  with  sounds  that  are  less  startling. 

The  dinner  bell,  which  is  supposed  to  be  one 
of  the  most  welcome  of  sounds,  could  state  its 
message  just  as  well  in  a  low,  clear,  musical 
tone  as  in  the  startling  noise  of  the  gong. 

Door  bells,  telephone  bells,  elevator  bells  could 
all  be  heard  just  as  well  if  their  sounds  were 
sweet,  clear,  and  musical  as  when  they  are  sting- 
ing and  rasping. 

These  are  some  of  the  noises  which  individu- 
als could  regulate  for  themselves.  The  other 
irritating  noises  of  city  life  which  one  cannot 
prevent,  he  should  get  as  far  away  from  as  pos- 
sible. If  one  must  work  in  the  city  during  the 
day,  he  can  select  for  his  dwelling  a  house  far 
enough  out  in  the  country  to  escape  from  the 
noises  at  night  when  he  goes  home  to  rest. 

There  are  people  who  have  harsh  voices   and 


HEARING  113 

others  who  raise  their  voices  to  loud,  shrill  tones 
in  speaking.  For  this  addition  to  unnecessary 
noise  no  one  is  excusable,  except  a  deaf  person 
who  cannot  hear  his  own  voice. 

School  children  get  in  the  habit  of  speaking 
in  high,  shrill  tones  by  trying  to  make  them- 
selves heard  above  their  playmates  while  at 
play,  or  while  talking  in  groups  out  of  school 
hours.  More  politeness  in  listening  to  one  another 
and  not  interrupting  while  another  is  speaking, 
would  to  a  great  extent  prevent  the  formation 
of  this  disagreeable  habit  of  shrill  speech. 

A  wise  teacher  in  a  large  private  school  used 
to  train  her  young  ladies  to  cultivate  pleasant 
voices  in  the  following  manner :  — 

She  would  send  one  to  the  highest  stair  at  the 
top  of  the  house  and  another  to  the  foot  of 
the  lowest  stair,  or  each  to  the  opposite  ends 
of  a  long  corridor,  and  then  ask  each  to  speak 
so  that  the  other  could  hear  distinctly,  but 
without  raising  the  voice.  In  this  way  strong 
tones  that  could  be  distinctly  heard  were  culti- 
vated without  the  disagreeable  sharpness  that 
comes  from  high  tones. 

One's  tone  of  voice  may  be  energetic  and  yet 

HALL'S  INT.   PHYS.  — 8 


114 


PHYSIOLOGY 


low,  clear,  sweet,  and  pleasant.  Such  a  voice 
one  should  cultivate,  both  as  a  duty  and  as  a 
means  of  pleasure  to  others. 


THINGS   TO   FIND    OUT 


Why  do  dogs  "prick  up  their  ears"  when 
they  hear  a  sound  which  they  seem  to  want  to 
hear  better? 


- 


CAN  You  HEAR  IT? 


Why  do  horses  turn  their  ears  backward  when 
their  driver  or  any  one  behind  them  speaks,  and 


SMELL  115 

forward  when  they  are  looking  at  some  object 
ahead  of  them  ? 

Why  do  horses,  dogs,  and  cats  resent  it  when 
one  puts  his  finger  into  their  ears? 

Do  animals  hear  more  acutely  than  men? 

SMELL 

THE  sense  of  smell  is  located  in  the  upper 
part  of  the  nose,  where  the  nerves  of  smell  are 
spread  out  over  the  lining  of  the  nose  like  a 
fan  (see  Fig.  17). 

This  sense  is  much  keener  in  lower  animals 
than  in  man ;  many  of  the  lower  animals  depend 
upon  their  sense  of  smell  for  finding  their  food. 

Dogs  that  live  with  men  have  a  much  less 
keen  sense  of  smell  than  wild  dogs. 

We  hardly  know  how  much  we  depend  upon 
the  sense  of  smell,  as  it  is  so  closely  linked  to 
the  sense  of  taste  that  sometimes  we  cannot 
tell  which  is  smell  and  which  is  taste. 

All  the  flavors  which  we  enjoy  so  much  in 
food  we  enjoy  through  the  sense  of  smell  as 
well  as  that  of  taste,  and  people  who  lose  their 
sense  of  smell  lose  also  a  large  part  of  then- 
sense  for  flavors. 


116 


PHYSIOLOGY 


The  sense  of  smell  is  specially  useful  in  detecting 
foul  air  that  might  make  us  ill  if  we  breathed  it. 


FIG.  17.  —  THE  ORGAN  OF  SMELL. 

Showing  the  many  branches  of  the  nerve  of  smell. 

This  figure  shows  the  nerves  well,  but  it  does  not  show  the  folds  which 
increase  so  much  the  surface  of  membrane,  and  through  that  increase 
the  acuteness  of  smell. 


The  sense  of  smell  is  impaired  by  colds,  and 
may  be  nearly  destroyed  by  catarrh.  For  this, 
as  well  as  for  other  reasons,  we  should  strengthen 
our  bodies  against  the  liability  of  taking  cold  as 
much  as  possible,  by  means  of  cold  baths,  proper 
diet,  and  breathing  pure  air. 


TASTE  117 

THINGS    TO    FIND    OUT 

Notice  how  an  animal  smells  by  holding  out 
to  it  some  object  with  which  it  is  not  familiar. 
Notice  it  "sniff"  the 
object.  What  is  "  sniff- 
ing," and  how  can  that 
improve  the  acuteness  of 
the  sensation? 

Why    can    one    smell 

,  i  •  i  i  ,1  SOMETHING  IN  THE  WIND. 

things    better   when   the 

wind  is  blowing  from  the  odorous  object  to  the 

observer  ? 

What  is  odor,  and  how  can  it  be  carried  by 
the  wind  ?  Can  an  object  finally  be  consumed 
by  constantly  smelling  of  it? 

TASTE 

THE  sense  of  taste  lies  in  the  tongue. 

The  top  of  the  tongue,  as  you  can  see,  is 
rough.  This  roughness  is  caused  by  many  little 
points,  in  each  one  of  which  there  are  nerve 
endings  (see  Fig.  18).  These  nerves  go  to  form 
large  nerves,  which  in  time  form  a  larger  nerve 
which  goes  to  the  brain. 


118 


PHYSIOLOGY 


In  order  to  taste  any  substance,  little  particles 
of  it  must  be  dissolved  in  the  saliva,  for  only  thus 
can  it  come  in  contact  with  the  nerves  of  taste. 


FIG.  18.— THE  UPPER  SURFACE  OF  THE  TONGUE. 

Showing  the  roughness  (papillse)  at  I  and  K.  At  H  and  L  there  are  very 
large  papillae  that  look  like  little  warts.  Beyond  the  root  of  the  tongue 
(D)  notice  the  epiglottis  (C).  E,  F,  and  G  represent  nerves  which  lie 
in  the  flesh  below  the  tongue. 

The  sense   of  taste   may  be  dulled,  and  thus 
made  of  less  service,  by  the  frequent  or  habitual 

no/"!       /~\-F      ti4-  v»^-Vfc  /••*»         Vfc /~\4-       o-r"\-i /^/-ici       r»  vk  r\        o/-\o  o/~vv\  TV^  /-v»ci 


use 


/  \j  j. 

of  strong,  hot  spices  and  seasonings. 


TASTE  119 

As  explained  above,  many  of  the  sensations 
which  are  called  taste  are  really  flavors;  that 
is,  they  are  sensations  which  depend  upon  both 
smell  and  taste.  Eat  a  piece  of  apple  or  a 
piece  of  turnip  while  holding  the  nose  tightly. 
Notice  that  the  sensation  is  very  different  from 
what  it  is  usually.  In  this  experiment  one  gets 
the  taste  only,  and  not  the  flavor  at  all.  The 
taste  of  these  two  substances  may  be  quite 
similar,  while  the  flavor  is  very  different. 

The  senses  of  smell  and  taste  are  like  the 
watchmen  in  the  town,  —  they  decide  whether 
or  not  a  thing  ought  to  come  in.  They  send 
word  at  once  to  the  brain  if  a  thing,  so  far  as 
they  can  tell,  is  unfit  to  eat. 

Without  these  guards  we  might  eat  many 
things  which  would  weaken  our  stomachs  and 
make  us  sick. 

Put  a  spoonful  of  salt  into  a  pint  of  water. 
After  the  salt  is  dissolved,  put  a  teaspoonful  of 
the  solution  into  nine  of  water,  and  see  if  you 
can  taste  it.  If  so,  put  one  of  this  strength 
into  nine  of  water,  and  see  if  you  can  taste  the 
salt.  How  dilute  a  solution  of  salt  can  you 
taste  ? 


120  PHYSIOLOGY 

TOUCH 

THE  sense  of  touch  is  given  by  some  of  the 
nerves  of  the  skin.  By  this  sense  we  can  tell  the 
shape  of  objects  and  whether  they  are  smooth  or 
rough.  The  nerves  of  touch  are  most  sensitive  on 
the  finger  tips  and  lips.  The  nerves  of  the  skin 
also  give  us  the  sense  of  heat  or  cold  and  the  sense 
of  pain. 

Persons  who  are  so  unfortunate  as  to  lose  the 
sense  of  sight  are  obliged  to  depend  largely  upon 
the  sense  of  touch  to  guide  them  when  they  are 
going  about  the  house  or  along  the  street. 

If  they  learn  to  read,  —  and  many  of  them  do, 
if  they  become  blind  early  in  life,  —  it  is  by  use 
of  the  sense  of  touch.  The  books  which  they  use 
are  printed  with  raised  characters,  and  they  read 
by  moving  the  fingers  along  the  lines  much  as  we 
glance  along  the  lines  with  our  eyes. 

The  sense  of  touch  may  be  trained  to  aid  in 
the  formation  of  cleanly  habits.  If  we  touch 
anything  that  is  soiled  and  sticky,  the  brain  is 
instantly  made  aware  of  it,  and  with  one  who 
is  accustomed  to  keep  his  hands  clean  the  mind 
is  not  at  ease  until  the  hands  are  washed. 


TOUCH 


121 


If  it  is  not  possible  to  wash  the  hands  at 
once,  then  one  should  remember  that  he  must 
not  put  his  fingers  to  his  mouth,  or  upon  any- 
thing that  is  to  be  eaten,  until  he  has  washed 


How  MUCH  CAN  You  TELL  BY  TOUCH  ? 

his  hands.  In  fact,  one  should  never  touch 
food,  nor  his  mouth,  nor  -his  eyes,  without  first 
washing  his  hands.  Germs  of  disease  are  very 
common  in  the  air.  They  are  carried  about  with 
the  dust  of  the  air,  and  there  may  be  some 
upon  almost  any  object  we  touch.  When  we  go 
about  in  public  places  we  touch  doors,  railings, 


122  PHYSIOLOGY 

and  various  other  objects  which  uncleanly  persons 
have  handled. 

A  soldier  was  once  seen  eating  a  banana  in  a 
way  that  could  easily  have  given  him  typhoid 
fever.  He  entered  a  railroad  car  with  a  valise 
in  one  hand  and  half  a  dozen  bananas  in  the 
other.  As  soon  as  he  was  seated  he  broke  off 
a  banana,  stripped  the  skin  entirely  off  and 
threw  it  out  of  the  window,  and  then  held  the 
bare  fruit  in  his  unwashed  hand  while  he  ate  it. 
If  he  had  realized  how  much  dirt  he  had  prob- 
ably collected  on  his  fingers  from  the  various 
objects  his  hands  had  touched  since  last  he 
washed  them,  he  would  undoubtedly  have  held 
the  banana  with  the  skin  on,  stripping  it  down 
only  as  fast  as  he  ate. 

It  is  true  that  one  may  take  into  the  mouth 
germs  of  disease  without  being  made  ill  by 
them,  because  when  one  is  entirely  well  he  is 
prepared  to  resist  the  work  of  such  germs.  But 
when  one  is  very  tired  or  faint  from  want  of 
food,  or  is  not  feeling  well,  disease  germs  may 
get  a  footing  before  the  system  is  strong  enough 
to  combat  them. 

For  this  reason  the  sense  of   touch   should  be 


TOUCH  123 

trained  to  remind  us  of  the  washbasin  and  towel 
whenever  we  are  to  use  our  hands  in  a  way 
that  could  bring  disease  germs  into  the  body. 

EXPERIMENTS 

Every  boy  or  girl  knows  what  tendrils  are, 
and  knows  that  grape  vines  and  pea  vines  climb 
by  means  of  them.  Find  a  tender,  open  tendril 
which  has  not  yet  found  anything  to  which  to 
cling.  Place  a  stick  beside  it  in  such  a  way  as  just 
to  touch  it  near  its  tip,  and  visit  it  several  times 
a  day  to  see  what  it  does.  When  you  have  found 
out  all  you  can  about  it,  write  an  essay  about 
u  Tendrils  and  what  they  do."  Perhaps  you  can 
think  of  experiments  other  than  the  one  described 
above. 

Let  one  member  of  the  class  be  blindfolded  and 
tested  with  various  objects  to  see  how  much  he 
can  tell  about  them.  Why  can  he  not  tell  the 
color? 

ALCOHOL    AND    THE    SENSES 

We  have  seen  how  necessary  our  senses  are  and 
how  helpless  we  should  be  without  them.  We  shall 
do  well  to  remember  that  the  use  of  alcoholic  drinks 
makes  all  of  the  senses  less  acute. 


124  PHYSIOLOGY 

There  was  once  a  time  when  men  used  to 
take  wine  or  brandy  or  some  other  alcoholic 
drink  when  they  had  anything  difficult  to  do, 
that  is,  when  they  had  on  hand  some  piece  of 
work  which  required  all  of  their  senses  to  be 
alert  and  all  of  their  powers  active. 

One  of  the  curious  things  about  alcohol  is 
that  it  makes  men  think  that  they  can  see  and 
hear  better  and  that  they  are  quicker  in  their 
movements.  As  soon  as  physicians  began  to 
experiment  with  alcohol,  it  was  found  out  that 
a  person  cannot  see  or  hear  so  clearly  or  act 
so  precisely  after  he  has  taken  a  little  alcohol 
as  he  could  before.  But  in  spite  of  this  fact, 
the  person  always  thinks  that  his  senses  and 
his  movements  are  improvedo 

So9  for  hundreds  of  years,  men  have  been 
fooled  by  alcohol.  They  have  taken  it  to  keep 
them  warm  in  winter,  when  it  really  cools  the 
body;  they  have  taken  it  to  make  them  cool  in 
summer,  when  it  makes  them  more  liable  to  be 
overcome  by  heat ;  they  have  taken  it  to  make 
them  strong,  when  it  really  makes  them  less 
strong;  and  they  have  taken  it  to  make  their 
senses  more  acute,  their  movements  more  pre- 


HOW  WE  THINK  AND  WHAT  WE  THINK  WITH     125 

else,  and  their  brains  more  active,  when  it  really 
dulls  all  of  the  senses  and  makes  the  brain  less 
acute  and  the  muscles  less  accurate  and  enduring. 


HOW  WE  THINK  AND  WHAT  WE  THINK 
WITH 

Do  you  remember  that  in  the  town  which  we 
looked  upon,  there  was  a  central  telephone  station 
from  which  messages  were  sent  all  over  the  town 
and  to  which  messages  were  coming  from  all 
parts  ? 

We  have  in  our  bodies  something  very  much 
like  this  central  station,  with  its  many  nerves  like 
the  wires  running  in  every  direction  to  carry 
messages  to  and  from  every  part  of  the  body. 

The  brain  is  the  center  of  all  our  thinking. 
It  directs  all  of  our  motions  and  regulates  our 
senses. 

In  the  picture  (Fig.  19)  you  can  see  the  two 
parts  of  the  brain  and  the  nerves  that  run  from 
the  brain  to  the  other  parts  of  the  body.  The 
nerves  carry  the  messages.  There  is  a  large  bun- 
dle of  nerves  which  passes  down  the  back.  This 
is  the  spinal  ^ord. 


126  PHYSIOLOGY 

From  the  spinal  cord,  branches  are  sent  out  to 
the  arms  and  legs.  All  of  these  nerves  branch 

and  branch  again  until 
every  part  of  the  body 
is  supplied  with  nerves. 

The  nerves  that  carry 
messages  of  seeing, 
hearing,  smelling,  tast- 
ing, feeling,  to  the  brain 
are  called  the  Nerves 
of  Sense,  but  those  that 
carry  messages  from  the 
brain  to  tell  the  muscles 
when  to  contract  or  re- 
lax are  called  Nerves  of 
Motion. 

Try  touching  your 
body  with  the  point  of 
a  needle,  and  see  if 

FIG.  19.—  IHE  BRAIN,  SPINAL  COED, 

AND  LABGE  NERVES.  you     Can     put     it     any- 

where  where  you  will  not  feel  it. 

This  wonderful  system  of  nerves  is  all  the  time 
sending  messages  to  the  brain  to  keep  it  informed 
of  everything  that  is  being  done  in  the  body. 
When  the  finger  touches  anything  hot,  the  nerves 


HOW  WE  THINK  AND  WHAT  WE  THINK  WITH     127 

send  the  thought  "  hot "  directly  to  the  brain  or  to 
one  of  the  nearer  nerve  centers,  and  the  brain 
sends  a  message  back  to  "  take  the  fingers  away." 

When  we  eat,  the  nerves  in  the  mouth  send 
word  to  the  brain  as  to  the  taste,  the  nerves  of  the 
nose  send  word  about  the  smell,  and  so  on. 

When  the  eye  sees  something  falling  near  us, 
the  word  is  sent  to  the  brain,  "  danger,"  and  the 
message  comes  back  to  the  muscles  of  the  legs,  or 
arms,  telling  them  what  to  do  to  escape  it. 

When  the  ear  hears  something  coming  upon  us, 
the  word  goes  to  the  brain  and  we  are  told  to  get 
out  of  the  way. 

In  this  way  message3  much  like  the  telephone 
messages  are  flying  along  the  nerves  all  of  the 
time. 

If  any  of  the  nerves  become  diseased,  they  cease 
to  do  their  work  well.  For  example,  if  the  nerves 
of  the  eye  are  injured,  one  sees  less  clearly  or 
perhaps  becomes  blind  because  the  nerves  of  sight 
do  not  send  messages  to  the  brain.  If  the  nerves 
of  feeling  become  diseased,  they  may  feel  too 
little  and  not  warn  one  of  danger. 

If  the  nerves  of  motion  are  diseased,  one  may 
move  when  he  does  not  wish  to,  —  that  is,  the  head 


128  PHYSIOLOGY 

or  some  other  part  of  the  body  will  shake.  Or  he 
is  unable  to  move  some  part  of  the  body  when  he 
wishes  to  do  so.  This  condition  is  called  paralysis. 

You  see  how  important  it  is  that  the  brain  and 
all  the  nerves  should  be  kept  in  the  best  possible 
order,  and  as  they  are  very  delicate  they  need  very 
good  care. 

If  you  look  again  at  Figure  19  you  will  notice 
that  the  upper  and  larger  part  of  the  brain  has  a 
folded  surface.  This  part  of  the  brain  is  called 
the  cerebrum.  Just  below  the  back  part  of  the 
cerebrum  is  the  small  and  nearly  smooth  cerebellum. 

The  cerebrum  is  the  organ  of  thought.  With  it 
we  feel  pain  or  pleasure,  sorrow  or  joy.  With  it 
we  reason,  and  we  decide  or  will  to  do  certain  acts 
or  to  speak  certain  words. 

The  cerebellum  receives  and  sends  out  messages, 
but  we  are  not  conscious  of  them ;  that  is,  we  do 
not  know  what  the  messages  are.  This  part  of 
the  brain  helps  us  to  balance  ourselves  when  we 
walk,  skate,  or  ride  a  bicycle.  The  cerebellum 
also  presides  over  the  action  of  muscles,  making 
the  muscles  of  the  arm,  for  example,  work  harmo- 
niously and  gracefully.  When  one  decides  to  reach 
for  a  certain  object  one  does  not  think  just  how 


EDUCATION  129 

much  each  muscle  must  contract  to  do  what  we 
wish.  It  is  the  cerebellum  that  performs  all  of 
these  details. 

EDUCATION 

£;•_-.•  THE  cerebrum,  the  cerebellum,  and  the  spinal 
cord  may  all  be  educated ;  that  is,  they  may  all 
be  taught  to  do  their  work  better.  The  cerebrum 
may  be  taught  to  feel  more  acutely  the  messages 
which  are  brought  to  it  from  the  eyes,  the  ears, 
the  tongue,  the  nose,  and  the  skin ;  it  may  be 
taught  to  think  more  clearly  about  the  feelings 
or  sensations  brought  to  it  by  the  nerves  of  sense ; 
and  it  may  be  taught  to  decide  more  quickly  what 
is  the  best  thing  to  do  or  to  say  under  different 
circumstances. 

To  educate  the  brain  to  feel  more  acutely  and 
accurately,  it  is  necessary  to  look  at  or  listen  to 
only  one  thing  at  a  time.  In  other  words,  to  give 
one's  whole  attention  to  one  thing  at  a  time. 

To  educate  the  brain  to  think  more  clearly,  it 
is  necessary  that  one  think  of  only  one  thing  at  a 
time. 

To  educate  the  brain  to  decide  questions,  or  to 
reason,  three  things  are  necessary:  (1)  attention  to 

HALL'S  INT.  PHYS. — 9 


130 


PHYSIOLOGY 


the  things  we  see,  or  hear,  or  smell,  or  taste,  or 
feel;  (2)  clear  thinking  about  the  things  we  see 
and  hear ;  and,  finally,  (3)  the  working  of  various 
problems  —  problems  in  arithmetic,  problems  in 

geography,  prob- 
lems in  language, 
and  problems  in 
physiology. 

The  playing  of 
games  is  a  very 
important  part 
of  an  education. 
Under  games  one 
may  include  all 
of  the  games  of 
the  kindergarten, 
marching  to  or- 
ders given  by  the  teacher  or  a  drillmaster,  and 
all  lawn  or  floor  games  where  one  person  or  one 
group  contests  for  points  against  another  person  or 
group  —  baseball,  football,  tennis,  croquet,  pris- 
oner's base,  archery,  quoit-pitching,  bowling,  etc. 
All  of  these  games  require  a  person  to  fix  the  atten- 
tion upon  one  thing,  to  think  quickly  and  clearly., 
and  to  decide  rightly.  The  systematic  playing  of 


UNDIVIDED  ATTENTION. 


EDUCATION 


131 


properly  chosen  games  is  as  important  as  any 
other  part  of  the  education,  and  if  neglected  puts 
one  at  a  disadvantage  throughout  life. 

The  best  health  of  thex  nervous  system  requires 
a  state  of  quiet  and  peacefulness.  The  feelings 
of  anger,  displeasure  or  irritation  are  unhealthful. 


If  some  act  of  another  person  displeases  us,  we 
are  doing  ourselves  an  injury  to  permit  a  feeling 
of  irritation  to  take  possession  of  us.  It  is  as  bad 
for  the  nerves  as  a  drink  of  pepper  tea  would  be 
for  the  stomach.  The  person  who  cherishes  kindly 
feelings  toward  others  benefits  himself  as  much 
as  the  person  to  whom  he  shows  the  kindness. 


132  PHYSIOLOGY 

THINGS    TO    FIND    OUT 

Describe  the  messages  that  go  to  and  from 
the  brain  if  a  thunder  shower  comes  up  when 
one  is  without  an  umbrella  a  short  distance  from 
home. 

What  would  be  the  result  if  no  such  messages 
could  be  sent  ? 

What  is  the  central  station  in  the  body  for  send- 
ing and  receiving  messages  ? 

What  happens  when  the  central  station  is  not 
in  a  condition  to  receive  or  to  send  out  messages 
properly  ? 

What  is  necessary  before  a  new  telephone  oper- 
ator at  a  central  station  can  become  expert  in 
changing  the  wires  and  making  connections  ? 

What  are  some  of  the  "  connections  "  that  must 
be  made  in  the  brain  if  one  has  to  get  ready  at 
short  notice  to  take  a  long  railroad  journey  ? 

What  are  some  of  the  "connections"  a  farmer 
must  make  in  putting  up,  taking  to  market,  and 
selling  at  a  profit,  a  load  of  garden  produce  ? 

What  is  necessary  to  make  the  mind  quick, 
accurate,  and  skillful  in  planning  and  carrying  out 
the  ordinary  work  of  life  ? 


SLEEP  133 

SLEEP 

Every  part  of  the  body  needs  rest  at  some  time. 
After  you  have  thought  of  that  a  little  while  you 
will  say,  "But  the  lungs  and  heart  never  rest." 
Are  you  sure  ? 

Notice  your  breathing  for  a  little  while.  When 
the  breath  is  drawn  in,  the  diaphragm  and  the 
muscles  of  the  chest  work ;  but  the  air  flows  out 
without  requiring  any  effort,  so  the  breathing 
muscles  rest  during  expiration.  In  this  way, 
while  the  lungs  always  keep  us  supplied  with 
air,  they  rest  a  part  of  the  time. 

The  heart,-  too,  works  night  and  day,  but 
after  each  beat  there  is  a  pause  during  which 
the  heart  rests. 

These  are  the  only  organs  that  have  to  work 
day  and  night,  and  all  the  rest  of  the  body 
depends  upon  the  sleeping  time  for  its  rest. 

The  body  would  very  quickly  wear  out  with- 
out this  needed  rest.  As  long  as  a  person  is 
awake  the  nerves  are  at  work  and  the  brain  is 
busy  thinking.  Not  only  does  the  body  need 
rest  after  a  day's  work,  but  the  brain  needs  it 
quite  as  much. 


134 


PHYSIOLOGY 


Although  one  is  asleep,  some  parts  of  the  brain 
may  go  on  working,  and  then  one  has  dreams. 

Grown  people  need  seven  to  eight  hours  of 
sleep  in  every  twenty-four,  but  children,  who 
use  so  much  strength  in  growing,  need  more 

sleep  than  that, 
and  the  best  time 
for  sleep  is  the 
early  part  of  the 
night.  Any  one 
who  wishes  to  do 
the  best  thinking, 
the  best  working, 
and.  to  excel  in 
the  school  games, 
must  go  to  bed 
early  and  have 
restful  sleep. 

Let  us  see  how 
we  can  get  the  best  rest  from  our  sleep.  We 
have  already  said  that  there  must  be  pure  air 
in  the  sleeping  room.  After  sleeping  in  a  poorly 
aired  room  one  is  likely  to  waken  with  a  headache 
or  to  feel  cross  when  he  first  gets  up,  and  that 
is  a  -poor  way  to  begin  the  day. 


FAST  ASLEEP. 


SLEEP  135 

Sleeping  with  the  mouth  open  is  a  very  bad  habit, 
and  may  lead  to  disease  of  the  throat  and  lungs. 

Eating  rich  food  or  much  food  of  any  kind 
just  before  sleeping  disturbs  the  sleep,  because 
the  stomach  has  to  keep  on  working.  If  it 


WIDE  AWAKB. 

becomes  distressed  in  any  way,  it  sends  messages 
to  the  brain  so  that  it  cannot  rest,  and  one  has 
bad  dreams. 

The  covering  of  the  bed  should  be  just  enough 
to  keep  one  warm;  too  much  covering  weakens 
one  and  makes  him  feel  listless  in  the  morning. 


136  PHYSIOLOGY 

When  one  wakens  naturally  from  a  good 
refreshing  sleep,  it  is  usually  time  to  get  up, 
and  it  does  more  harm  than  good  to  lie  in  bed 
after  that  time. 

Let  us  review  this  lesson  a  moment :  — 

Go  to  bed  early. 

Breathe  pure  air. 

Breathe  through  the  nose. 

Do  not  eat  rich  food  just  before  going  to  bed. 

Sleep  under  light  covering. 

Get  up  when  you  waken. 

SOME   ENEMIES    OF   THE    BODY 

IF  the  people  in  our  town  knew  that  just 
outside  of  the  town  were  enemies  who  would 
spoil  their  telephone  system  that  had  been  made 
so  carefully  to  meet  every  need  of  the  town ; 
would  weaken  their  policemen  so  that  they 
would  no  longer  guard  the  city  so  faithfully ; 
would  tamper  with  .the  food  so  that  it  would 
not  be  so  healthful ;  would  even  rob  the  people 
of  their  appetite  for  food ;  and  would  take  away 
their  wish  to  improve  the  town,  —  do  you  think 
they  would  sit  quietly  down  and  say,  "  Let  them 


SOME  ENEMIES  OF  THE  BODY  137 

come  in,  we  can  put  them  out  easily  if  we  do 
not  want  them."  Or,  worse  than  that,  would 
the  people  invite  them  in,  saying,  "  Perhaps  they 
will  not  hurt  our  town  so  much  as  they  have 
hurt  other  towns  they  have  entered." 

Alcohol  and  tobacco  are  the  enemies  that  will 
do  for  the  body  what  these  enemies  would 
do  for  a  town.  Your  nervous  system  is  much 
more  delicate  than  a  city  telephone  system. 
Alcohol  and  tobacco  are  narcotics  and  dull  the 
senses.  They  irritate  the  lining  of  the  stomach, 
but  at  the  same  time  dull  the  sense  of  feeling 
so  that  the  nerves  of  the  stomach  do  not  send 
word  to  the  brain  of  the  trouble  there,  and  the 
one  who  has  used  the  alcohol  does  not  know  of 
the  harm  being  done. 

If  on  a  cold  day  one  should  take  an  alcoholic 
drink,  his  nerves  would  not  tell  him  how  cold 
it  is,  and  the  brain  would  send  no  word  of  warn- 
ing that  would  lead  him  to  protect  himself  or 
keep  him  from  freezing.  Drinking  men  arc 
much  more  easily  affected  by  the  cold  than  are 
other  men. 

Not  only  the  nerves,  but  the  great  nerve  cen- 
ter, the  brain,  is  injured  by  alcohol  and  by 


138  PHYSIOLOGY 

tobacco  too.  A  person  who  has  been  drinking 
much  does  not  know  what  he  is  talking  about, 
he  says  foolish  things,  he  does  not  know  what 
he  is  doing,  and  does  many  things  of  which  he 
is  ashamed  when  sober.  When  a  man's  mind 
cannot  control  his  talking  or  his  acting  there 
must  be  something  wrong  with  it.  You  may 
think  that  this  bad  effect  lasts  only  so  long  as 
the  man  is  drunk,  but  that  is  not  so.  Each 
time  that  the  brain  is  affected  it  becomes  weaker, 
until  after  a  time,  even  though  the  man  may 
now  use  no  alcohol  at  all,  he  cannot  think  so 
well  as  he  used  to  think  before  he  began  the  use 
of  alcohol. 

Tobacco  has  a  terrible  effect  upon  the  brain 
and  nerves  of  a  young  person.  So  clearly  do 
people  realize  this  bad  effect  of  tobacco  that 
more  than  half  the  states  in  the  Union  have 
made  laws  to  keep  people  from  selling  any  form 
of  tobacco  to  boys. 

Boys  sometimes  think  that  cigars  are  bad,  but 
think  no  harm  can  come  from  so  small  a  thing 
as  a  cigarette.  That  is  a  great  mistake.  Through 
cigarettes  alone  many  boys  have  been  stunted  in 
growth,  have  been  made  so  nervous  that  the 


SOME   ENEMIES  OF   THE   BODY 


139 


hands  trembled,  and  have  weakened  their  brain 
power  until  they  could  no  longer  keep  up  with 
their  grades  at  school.  In  many  instances,  too, 
these  were  boys  who  before  using  cigarettes  led 
their  classes. 


A  STEADY  NEKVE. 

How  the  story  of  William  Tell  thrills  us !  All 
the  world  admires  such  a  cool  head  and  such 
steady  nerves.  The  picture  shows  the  proud 
and  tyrannical  Gessler  demanding  of  Tell  what 
he  intended  to  do  with  the  second  arrow.  Such 
a  test  as  that  may  never  again  be  made  of  a 


140  PHYSIOLOGY 

man,  but  other  crises  come  in  the  life  of  every 
person.  When  these  tests  come  one  needs  to 
have  a  clear  eye,  a  steady  hand,  and  a  power  of 
quick  decision  and  strong  action.  The  men  who 
possess  all  of  these  qualities  are  the  men  who 
succeed  in  life,  while  the  men  who  do  not  pos- 
sess them  either  fail  completely  or  make  a  less 
marked  success  than  they  could  have  made  with 
all  of  their  faculties  trained  and  alert.  When  we 
know  what  alcohol  does  for  the  senses  and  the 
brain  and  muscles,  it  seems  strange  that  people 
should  ever  touch  a  drop  of  it. 

The  white  corpuscles  that  guard  the  body  from 
harm  are  very  much  weakened  by  the  use  of 
alcohol,  so  much  so  that  they  cannot  drive  off 
disease  so  well  as  they  can  when  healthy,  and 
therefore  drinking  men  take  disease  much  more 
quickly  than  others  do. 

Some  of  the  largest  insurance  companies  will 
no  longer  insure  men  who  drink  at  all,  just 
because  statistics  show  that  such  men  take  dis- 
ease more  quickly. 

Many  large  railway  companies  will  not  em- 
ploy men  who  are  known  to  use  alcohol  even 
in  small  amounts. 


THE  USE  OF   TOBACCO  141 

WHAT  DOCTORS  AND  TEACHERS  SAY 
ABOUT  THE  USE  OF  TOBACCO 

"  A  CERTAIN  doctor,  struck  with  the  large  num- 
ber of  boys  under  fifteen  years  of  age  whom  he 
observed  smoking,  was  led  to  inquire  into  the 
effect  the  habit  had  upon  their  general  health. 
He  took  for  this  purpose  thirty-eight  boys,  aged 
from  nine  to  fifteen  years,  and  carefully  examined 
them,  and  in  twenty-seven  of  them  he  discovered 
injurious  traces  of  the  habit.  In  twenty-two  there 
were  various  disorders  of  the  circulation  and  diges- 
tion, palpitation  of  the  heart,  and  more  or  less 
marked  taste  for  strong  drink.  In  twelve  there 
was  frequent  bleeding  of  the  nose ;  ten  had  dis- 
turbed sleep ;  and  twelve  had  slight  ulceration  of 
the  mucous  membrane  of  the  mouth,  which  dis- 
appeared on  ceasing  from  the  use  of  tobacco  for 
some  "days.  Medical  treatment  was  of  little  use 
till  the  smoking  was  discontinued,  when  health 
and  strength  were  soon  restored."  —  British  Medi- 
cal Journal. 

"The  use  of  tobacco  in  any  form  previous  to 
sixteen  years  of  age  has  an  undoubted  tendency 
to  lower  very  materially  the  mental  force  and 


142  PHYSIOLOGY 

acumen,  and  to  render  the  user  a  person  without 
ambition,  and  may  even  cause  insanity  or  idiocy." 
—  N.  B.  DELAMATER,  M.  D.,  Specialist  in  Mental 
and  Nervous  Diseases. 

"In  over  twenty  years  of  experience  as  a 
teacher  I  cannot  recall  a  single  boy  who  main- 
tained a  high  average  in  his  classes  and  used 
tobacco,  and  further,  some  who  were  very  bright 
and  stood  well  in  their  classes  lost  their  standing 
when  they  acquired  the  tobacco  habit."  —  JONA- 
THAN K.  TAYLOR,  Baltimore,  Md.,  formerly  Prin- 
cipal Taylor  Academy,  Wilmington,  Del. 

The  government  of  the  United  States  of 
America  has  prohibited  the  use  of  the  cigarette 
at  West  Point  and  Annapolis,  on  sanitary  and 
moral  grounds.  Many  colleges  prohibit  its  use. 
Dr.  J.  W.  Seaver  of  Yale  College  says,  "  Out  of 
our  highest  scholarship  men  only  a  very  small 
percentage  (about  five)  use  tobacco,  while  of  the 
men  who  do  not  get  appointments,  over  sixty 
per  cent  are  tobacco  users." 

James  E.  Armstrong,  Englewood  High  School 
and  President  of  Board  of  Trustees  of  University 
of  Illinois,  said:  "  There  are  few  cigarette  smokers 
in  the  high  school.  Smokers  usually  fail  to  go 


THE    USE   OF   TOBACCO  143 

through  the  grammar  school.  Few  ever  gradu- 
ate who  smoke  before  they  enter  the  high  school. 
As  a '  rule  the  smoker  is  dull  and  unable  to 
concentrate  his  attention  upon  his  work.  It  is 
difficult  to  arouse  him  to  any  degree  of  enthusi- 
asm. So  long  as  men  indulge  in  smoking  it  will 
be  hard  to  persuade  the  boys  that  they  should 
shun  it,  and  so  long  as  boys  continue  to  learn 
the  habit  there  will  be  men  to  perpetuate  it." 

You  may  sometimes  hear  people  say  that 
there  is  no  harm  in  drinking  a  little  wine  or 
beer,  or  in  smoking  or  chewing  tobacco  "  a 
little,"  if  one  does  not  take  "too  much."  They 
will  tell  you  that  one  should  have  such  a 
strong  will  and  such  self-control  that  he  will 
be  able  to  stop  when  he  has  taken  only  a  little. 
This  would  be  true  if  alcohol  and  tobacco  acted 
upon  the  body  as  food  does,  simply  making  us 
ill  when  we  take  too  much.  But  these  sub- 
stances, alcohol,  tobacco,  opium,  and  other  narcot- 
ics, affect  the  mind  in  such  a  way  as  to  weaken 
that  very  self-control  that  is  needed  to  keep 
one  from  taking  more  than  a  little.  Great  men 
of  science  have  found  by  careful  and  ingenious 
tests  that  one  of  the  first  effects  of  only  a  little 


144  PHYSIOLOGY 

alcohol  in  the  body  is  to  weaken  the  power  of 
self-control.  No  one  can  tell,  therefore,  when  he 
takes  the  first  little  how  much  more  he  may  be 
led  into  taking. 

THE   BODY   FRAMEWORK 

IF  the  entire  body  were  as  soft  as  the  organs 
about  which  we  have  already  studied,  the  body 
would  lie  all  in  a  heap  together  and  we  could 
neither  stand  nor  walk. 

A  body  that  could  not  stand  nor  walk  could 
do  very  little  in  the  world.  There  are  some  ani- 
mals that  are  in  this  condition,  but  they  belong 
to  a  very  low  order  of  animals. 

We  have  within  us  a  strong,  hard  framework 
that  gives  support  to  the  entire  body.  The  back- 
bone, the  hip  bones,  the  leg  bones,  and  the  shoulder 
and  arm  bones  support  the  entire  body.  By  press- 
ing upon  different  parts  of  your  body  you  can  feel 
some  of  the  bones  of  this  framework. 

You  need  not  be  told  how  bones  look,  for  every 
child  has  seen  bones,  if  not  the  bones  of  a  per- 
son, certainly  the  bones  of  chickens,  cows,  and 
sheep,  and  all  bones  look  a  good  deal  alike.  That 
is,  they  are  hard  and  white  on  the  outside. 


THE  BODY  FRAMEWORK 


145 


The  hardness  is  given  to  the  bones  by  lime, 
but  there  is  also  a  jellylike  part,  which,  when 
boiled  out,  makes  gelatine.  If  the  long  bones  of 
the  body  were  solid,  they  would  be  very  heavy  to 
carry  around,  but  they  are  hollow, 
and  this  hollow  part  is  filled  with 
a  soft,  fatty  substance  called  mar- 
row (Fig.  20). 

You  have  seen  the  marrow  of 
a  soup  bone,  perhaps,  and  have 
noticed  the  yellowish  color  it  has. 
The  blood  vessels  come  up  through 
the  marrow  and  in  tiny  openings 
in  the  bone,  bringing  the  food 
that  makes  the  bones  grow.  The 
blood  flows  even  through  the 
bones. 

Showing    the    hollow 

In  a  little  baby  the  bones  have     part  <&),  which  is 

.     ,  ,      .  .  filled  with  marrow. 

more  of  the  gelatine  matter  than 

they  have  of  lime,  and  they  are,  therefore,  soft  and 

easily  bent. 

Even  half-grown  children  have  softer  bones 
than  grown  people,  and  that  is  why  they  can 
tumble  about  so  much  without  breaking  their 
bones.  It  is  also  the  reason  why  children  must 

HALL'S  INT.  PHTS.  — 10 


'.— A  PART  o» 
THE  THIGH  BONE. 


146 


PHYSIOLOGY 


be  careful  to  stand  straight  and  sit  straight.  The 
bones,  being  soft,  will  readily  take  a  position  and 
will  then  grow  in  that  way. 

Sometimes  school  children  sit 
low  in  their  seats,  bending 
the  back  instead  of  sitting  erect 
(see  Fig.  21);  or  sit  with  one 
arm  upon  the  desk,  raising  one 
shoulder  higher  than  the  other ; 
both  of  these  and  similar  habits 
cause  a  curving  of  the  back- 
bone. 

If  you  wish  to  add  strength  to  your  bones,  you 
must  have  lime  in  some  way.     Do  you  remember 


Fia.  21.— IMPROPER  AND  PROPER  POSITIONS  IN  SITTING. 


THE  SKELETON  147 

which  foods  are  best  for  furnishing  to  the  bones 
the  lime  which  they  need  while  they  are  growing-? 

Pure  air  and  sunlight  are  also  necessary  to 
healthy  growth  of  the  bones. 

The  muscles  are  all  fastened  in  some  way  to 
the  framework  or  skeleton;  without  this  support 
they  could  not  hold  tight  enough  to  lift  the  legs 
and  arms  and  turn  the  body.  If  you  have  the 
leg  bone  of  a  chicken  or  sheep  to  look  at,  per- 
haps you  can  find  upon  the  bone  the  ridges  to 
which  the  muscles  were  fastened. 

THE   SKELETON 

I.    JOINTS 

THE  skeleton  is  not  all  in  one  piece.  If  it 
were  we  could  not  bend,  could  not  pick  up  things 
with  our  fingers,  could  not  eat,  nor,  indeed,  do 
any  of  the  work  which  we  now  do.  Think  how 
stiffly  you  would  walk  if  there  were  no  bend  in 
your  legs,  and  how  awkward  you  would  be  with 
no  bend  in  your  arm.  Think  how  little  you 
could  do  with  your  fingers  if  they  would  not 
bend. 

The  bones  are  of  very  different  lengths,  joined 


148 


PHYSIOLOGY 


together  in  such  a  way  that  the  ends  can  move.  The 
place  where  the  bones  come  together  is  called  &  joint. 
Some  of  the  joints  bend  back 
and  forth  like  the  hinge  on  the  door 
(Fig.  22),  while  others  bend  in  any 
direction.  The  first  kind  are  the 
hinge  joints,  and  the  second  kind 
the  ~ball  and  socket  joints  (Fig.  23). 
Can  you  find  in  your  body  one  or 
more  of  each  kind  ? 

Bones  are  not  all  of  the  same  shape, 
by  any  means,  but  are  long  or  short, 
i,  humerus;  2,  ulna,  flat  (see  Fig.  24)  or  round,  accord- 
ing to  the  work  they  have  to  do. 


FIG.  22. —  HINGE 
JOINT  OF  THE 
ELBOW. 


FIG.  23. — A  JOINT  THAT  TURNS 
IN  ANY  DIRECTION  — THE  HIP 
JOINT. 

This  is  a  ball  and  socket  joint. 


FIG.  24. —  A  FLAT  BONE — THE 
SHOULDER  BLADE. 


THE  'SKELETON  149 

H.     BONES   FOR   PROTECTION 

Bones  have  two  special  uses :  (1)  to  support 
the  body;  and  (2)  to  protect  the  delicate  parts. 
Most  of  the  bones  which  are  used  for  sup- 
port are  round  and  long,  while  many  of  those 
that  protect  are  flat. 
There  are  some  parts 
of  the  body  that  are 
so  soft  and  delicate 
that  a  fall  or  a  blow 
upon  them  would 
crush  them. 

These      delicate     OP-    Flo.  25.— THE  RIBS  AS  THEY  OUGHT 

•n  i  TO  BE. 

gans    all    need   some 

hard  covering  that  will  neither  crush  nor  break 
easily,  and,  as  usual  in  nature,  where  there  is  a 
need  there  is  also  a  supply.  The  bones  are  so 
arranged  as  to  form  this  protection. 

If  you  look  at  the  picture  (Fig.  25),  you  can  see 
the  rib  bones  extending  out  from  the  backbone, 
and  joining  the  breast  bone,  thus  making  a  space 
in  which  the  lungs  and  heart  can  be  safely  stored 
and  protected.  The  lower  ribs  extend  down  far 
enough  to  cover  the  liver  and  stomach. 


150 


PHYSIOLOGY 


There  is  just  one  organ  more  delicate  than 
those  of  which  we  have  spoken,  and  that  is  the 
brain,  and  for  this  organ  there  has  been  made  a 


FIG.  26.  —  SIDE  VIEW  OF  THE  SKULL. 

Showing  the  most  important  bones  of 

the  skull,  and  their  names. 


FIG.  27. —  TOP   VIEW  OF  THE 
SKULL. 


Showing  the  crooked  seams  or 
sutures  where  the  bones  are 
joined. 


boxlike  covering  that  pro- 
tects   it    on     every     side. 

Look  at  the  picture  (Fig.  26),  and  you  will 
see  how  the  -bones  are  put  together  to  form 
a  somewhat  spherical  box  in  which  the  brain 
lies. 

This  box  is  not  all  of  one  piece,  but  is  formed 
of  eight  beautifully  fitted  bones  whose  edges  fit 
together  like  two  saw-tooth  edges,  as  shown  in 
Figure  27. 


EFFECT  OF  ALCOHOL  AND  TOBACCO          151 

EFFECT   OF  ALCOHOL   AND   TOBACCO 
UPON  THE  BONES 

EVERY  boy  wishes  to  grow   into  a  large  and 
strong  man.     Physicians  who  have  made  a  study 


A  FINE  FIGURE. 


of  the  things  which  help  or  hinder  the  growth  of 
children  and  youths  agree  that  the  use  of  tobacco 
and  alcohol,  also  of  strong  tea  and  coffee,  injure 
young  people  and  hinder  their  proper  growth  and 
development.  If  a  boy  becomes  a  soldier  he 


152  PHYSIOLOGY 

wants  to  stand  near  the  head  of  the  company 
among  the  tall  men ;  if  he  represents  his  school  or 
college  on  an  athletic  team  he  wants  strong  legs 
and  arms  and  long  legs  and  arms.  The  length  of 
the  legs  and  arms  as  well  as  the  height  of  the  body 
depends  upon  the  growth  of  the  bones.  Boys  and 
girls  and  youths  who  use  alcoholic  drinks  or  other 
narcotics  cannot  grow  into  so  large  or  so  strong 
men  and  women  as  they  could  if  they  used  the 
foods  and  drinks  which  are  intended  by  nature 
for  use. 

Name  the  principal  articles  of  a  natural  diet  for 
mankind. 

Name  some  of  the  .things  that  must  be  avoided 
if  one  would  have  a  fine,  strong,  properly  shaped 
body. 

THE   FRAMEWORK    OF  OTHER   ANIMALS 

THERE  are  animals  lower  than  man  that  have 
skeletons  almost  like  ours  (see  Fig.  28).  At 
first  thought  a  cat  seems  to  be  a  very  different 
shape  from  a  baby,  and  yet  both  have  about  the 
same  number  and  -  kinds  of  bones  of  about  the 
same  shape. 


THE   FRAMEWORK  OF  OTHER  ANIMALS       153 

The  cat,  dog,  cow,  horse,  pig,  and  all  such 
animals  use  all  four  limbs  for  walking,  while 
we  use  only  our  hind  limbs  for  walking  and 


Giraffe  Elephant  Lion  Man 

Fio.  28.  —  SKELETONS  OF  BACK-BONED  ANIMALS. 

Look  for  the  elbows  of  all  the  animals.    Look  for  the  knees ;  the  wrists ; 
the  ankles ;  the  heels. 

our  front  ones  for  lifting,  carrying,  and  other  such 
work. 

The  body  of  the  bird  seems  still  less  like  ours 
than  does  that  of  the  sheep  or  the  cow,  and  yet 
when  the  feathers  are  off  we  find  the  bird  has 


154  PHYSIOLOGY 

just  about  the  same  kind  of  a  framework  as  we 
have.  The  bird  uses  the  hind  limbs  for  walking 
and  the  front  ones  for  flying.  Even  the  frog  skele- 
ton is  in  a  general  way  like  your  own  (Fig.  29). 

The  foot  of  a  horse  or  cow  or  sheep  does  not 
look  at  all  like  your  own  foot,  and  yet  if  you  look 
at  the  picture  (Fig.  30),  and  compare  it  with  the 


FIG.  29.— SKELETON  OF  THE  COM-   FIG.  30.  —  BONES  OF  HUMAN 
MON  FROG.  LEG  AND  FOOT,  AND  MUSCLES 

OF  CALF. 

leg  and  foot  of  the  lion  or  elk,  you  will  see  that  it 
is  not  so  much  the  bones  that  are  different,  as  the 
way  in  which  they  are  used. 

The  cow  walks  on  her  toes  and  keeps  her  heel 
in  the  air,  while  we  keep  ours  down  on  the 
ground.  The  middle  joint  on  a  cow's  hind  leg 
corresponds  to  the  heel,  and  the  middle  joint  on 
her  front  leg  to  the  wrist.  The  horse  walks  on 
his  middle  toe,  and  in  this  way  seems  to  have  a 


THE  FRAMEWORK   OF  OTHER  ANIMALS       155 

foot  with  a  hoof  and  no  toes  or  nails;  but  the 
horse's  hoofs  and  the  hoofs  of  all  animals  corre- 
spond to  oiir  finger  nails  and  toe  nails. 

The  joint  on  the  horse's  fore  limb  that  looks 
like  his   knee  is  really  his  wrist  joint,  and  the 


hip 


FIG.  31.  —  HORSB. 

one  higher  is  the  elbow  joint,  while  the  hip  and 
shoulder  joints  are  quite  out  of  sight  (Fig.  31). 
The  turtle,  whose  body  at  first  thought  seems 
to  be  quite  unlike  our  own  bodies,  when  looked 
at  without  his  shell  and  his  muscles,  is  found  to 
have  a  skeleton  very  little  different  from  ours. 


156  PHYSIOLOGY 

HOW  THE   BODY  MOVES 

WE  have  learned  that  the  nerves  send  word 
to  any  part  of  the  body  to  tell  it  to  move,  and 
that  the  bones  are  so  made  that  they  can  move, 
but  nothing  has  yet  been  said  of  the  muscles 
which  give  us  the  power  of  motion. 

Lean  beef  is  the  muscle  of  the  ox,  lean  pork 
the  muscle  of  the  pig.  Our  muscle  looks  much 
the  same  as  beef  muscle  before  it  is  cooked. 

Muscles  are  made  of  many  bundles  of  fibers 
or  threads  fastened  together  by  a  web  as  thin 
as  tissue  paper.  In  meat  that  has  been  well 
boiled,  these  fibers  can  be  easily  pulled  apart; 
sometimes  they  even  fall  apart. 

Muscle  fibers  are  bound  together  in  many 
sizes  and  shapes  to  fit  the  work  they  have  to 
do.  The  muscles  of  the  eye  are  very  small 
indeed,  while  the  muscles  of  the  legs  are  long 
and  large. 

If  you  take  a  piece  of  rubber  and  stretch  it, 
you  will  find  that  it  grows  longer  and  thinner 
at  the  same  time,  and  when  you  let  go  it  draws 
quickly  back  again  to  its  first  size.  The  muscles 
are  able  to  tighten  up  or  contract,  becoming 


HOW  THE  BODY  MOVES  157 

shorter  and  thicker,  and  then  to  relax  or  go 
back  to  their  first  size. 

This  power  of  the  muscle  to  contract  and  relax 
is  the  power  that  moves  the  body. 

With  your  left  hand  take  hold  of  your  right 
upper  arm,  and  then  bend  your  right  arm  up 


Fio.  32.— DIAGRAM  TO   SHOW  THE  ACTION  OF  THE  BICEPS  MUSCLE 
OF  THE  ARM. 

to  the  shoulder;  can  you  not  feel  the  muscle 
under  your  hand  getting  thicker?  (See  Fig.  32.) 

The  muscle  on  the  upper  arm  is  fastened  to 
the  shoulder  and  to  the  fore  arm  just  below  the 
elbow.  When  that  muscle  gets  shorter  or  con- 
tracts, the  arm  must  come  up,  and  when  the 
muscle  gets  longer  again,  or  relaxes,  the  arm 
must  go  down. 

Shut  your  fist  up  tightly  and  look  at  your 


158  PHYSIOLOGY 

wrist.      Do   you    see   those    strong   cords?   (Fig. 

33.)  They  are  joined  to  the  ends  of  the  muscles 
and  fasten  them  to  the  bones.  The 
cords  and  tendons  are  not  at  all 
elastic,  and  they  hold  on  to  the 
bones  so  tightly  that  they  must 
move  when  the  muscles  pull  on 
the  tendons. 

If  you  can  get  a  chicken's  or 
turkey's  foot  and  leg,  you  can  cut 
open  the  yellow,  scaly  skin  of  the 
leg  and  you  can  see  the  heavy 
white  tendons,  and  by  pulling  them 
find  out  what  part  of  the  foot  is 
moved  by  them. 

The  stronger  and  larger  a  muscle 
is  the  more  it  can  move  or  lift. 

MusciEs~ND  The  size  and  st^ngth  of  the  muscles 
TENDONS    OF  rQav  j^  increased  by  using;  them. 

THE       LOWER 

ARM-  If   a   person   wants   to   be   strong 

Showing  also  the  ,  ,.<,,       -.  .    , 

ligament  encir-  enough    to    lift    heavy    weights,   to 


ding  the  wrist.    uke   jong   walkg?  to    run    fagt?  t() 

and  swim,  he  must  use  his  muscles  a  little  each 
day  at  first,  and  then  more  and  more  each  day 
until  he  becomes  strong. 


THE   CAKE  OF  THE   MUSCLES  159 

The  muscles  have  to  be  fed  enough  good  blood 
to  enable  them  to  make  all   the  motions  of  the 


RUNNING  is  GOOD  EXERCISE. 

body,  and  to  give  all  the  heat  needed  to  keep 
the  body  warm. 

THE  CARE   OF  THE  MUSCLES 

BY  this  time  you  are  all  sure  of  one  thing,  and 
that  is  the  need  for  good  food  and  the  wastefulness 
of  eating  things  simply  because  they  taste  good. 

We,  of  course,  want  our  food  to  taste  good,  but 
food  that  only  tastes  good  and  does  not  nourish 
makes  the  body  a  great  deal  of  work,  which 
simply  helps  to  wear  it  out  without  helping  to 
build  it  up. 


160  PHYSIOLOGY 

There  are  some  things  which  people  get  into 
the  habit  of  eating  and  drinking  which  do  them 
no  good  at  all,  and  others  still  that  do  them  real 
harm  ;  but  yet  they  are  taken  because  they  leave 
a  pleasant  feeling. 

If  it  is  foolish  to  take  food  or  drink  that  does 
no  good,  is  it  not  still  more  foolish  to  take  that 
which  does  harm  ? 

The  fat  of  the  body  cannot  contract  or  relax  as 
the  muscles  can,  and  therefore  it  has  no  strength 
and  no  power  of  motion. 

If  a  boy  or  man  wishes  to  be  strong,  he  must 
build  up  muscle  and  not  fat.  Fat  is  nature's  way 
of  laying  aside  material  that  it  cannot  use.  A 
good  deal  of  fat  often,  but  not  always,  shows  that 
a  person  is  eating  too  much. 

Beer,  wine,  and  cider  often  tend  to  change  the 
muscles  to  fat  and  weaken  them  very  much. 
Sometimes  the  fat  collects  around  the  muscles 
and  crowds  them  so  that  they  become  weak. 

Men  who  drink  beer  often  become  fat  and 
look  very  heavy,  but  they  are  not  so  strong  as 
they  would  have  been  without  the  beer. 

When  men  or  boys  are  training  to  do  some  feat 
of  skill  which  needs  steady  nerves  and  strong 


THE  CARE  OF   THE  MUSCLES  161 

muscles,  they  are  not  allowed  to  use  anything 
that  has  alcohol  in  it,  nor  are  they  allowed  to 
use  tobacco.  Football  teams,  track  teams,  men 
who  are  to  win  the  boat  races  and  foot  races  for 
schools  and  colleges,  are  not  allowed  by  their 
trainers  to  use  beer,  wine,  or  cider,  or  any  drink 
that  contains  alcohol.  They  are  not  allowed  to 
use  tobacco,  or  even  strong  tea  and  coffee. 

Governments  are  learning  that  soldiers  cannot 
march  so  long,  or  stand  the  hardships  of  war  so 
well,  when  they  have  had  alcoholic  drinks ;  and  in 
Germany,  France,  and  England  they  no  longer 
give  alcohol  to  the  soldiers  when  there  is  fight- 
ing or  hard  marching  to  be  done. 

It  used  to  be  a  general  custom  on  board  of 
war  ships  to  serve  out  alcoholic  liquors  to  the 
men  just  before  a  battle  to  "  give  them  courage." 
This  custom  is  no  longer  followed  in  the  American 
navy,  and  the  folly  of  the  custom  was  very  clearly 
shown  at  the  battle  of  Santiago  in  the  recent 
Spanish-American  war. 

Just  before  the  Spanish  fleet  sailed  out  of  the 
harbor  to  run  past  the  American  vessels,  wine  and 
other  alcoholic  liquors  were  served  out  to  the 
Spanish  sailors.  On  the  American  vessels  no 

HALL'S  INT.  PHYS. — 11 


162 


PHYSIOLOGY 


liquor  was  served,  but  every  man '  at  the  given 
signal  stood  at  his  gun  with  clear  brain  and 
steady  nerves.  The  result  was  that  the  Spanish 
gunners  fired  wildly  and  their  shots  were  with- 
out effect,  while  the  American  gunners  fired  true 
to  the  mark  and  not  a  Spanish  vessel  escaped. 


THE  OREGON  IN  THE  BATTLE  OF  SANTIAGO. 

Tobacco  makes  the  muscles  weak  and  soft. 
Have  you  noticed  how  boys  who  smoke  cigarettes 
like  to  lounge  about  and  lean  on  something? 
Did  you  ever  see  a  boy  smoker  walking  briskly 
and  looking  as  energetic  as  the  boy  who  never 
smoked  ?  Men  smokers  sometimes  do,  but  boys 


EXERCISE  163 

are  using  so  much  energy  in  growing  that  they 
cannot  afford  to  lose  any  by  smoking. 

The  heart  is  largely  made  of  muscles,  and  any- 
thing that  affects  the  muscles  affects  the  heart. 
The  tobacco  that  weakens  the  other  muscles  also 
weakens  the  heart.  If  part  of  the  muscles  of  the 
heart  are  changed  to  fat  by  alcohol,  they  become 
too  weak  to  send  the  blood  over  the  body  with 
force,  and  some  or  many  parts  of  the  body  will 
suffer. 

EXERCISE 

THE  child,  or,  indeed,  the  man,  who  wishes  to 
be  strong,  must  use  his  muscles. 

Why  is  it  that  one  person  can  walk  five  or  ten 
miles  without  being  tired,  while  another  cannot 
walk  one  mile  without  being  tired  ? 

It  may  be  any  one  of  several  reasons.  The  per- 
son who  cannot  walk  well  may  have  too  much  fat 
instead  of  muscle,  or  his  lungs  may  not  be  able  to 
take  in  air  enough  for  brisk  exercise,  or  he  may 
be  sick  in  some  other  way ;  but  it  is  much  more 
likely  to  be  that  he  has  not  used  his  walking  mus- 
cles. If  we  want  to  be  strong  in  a  particular  way, 
we  must  exercise  the  muscles  that  do  that  kind  of 


164 


PHYSIOLOGY 


work ;  and  to  be  strong  all  over  we  must  exercise 
all  the  muscles. 

The  very  best  way  of  exercising  is  through  out- 
of-door   games.      There  is  nothing  else  that  will 
take  the  place  of  these,  because  they 
exercise    all    the    muscles    of    the 
body,  and  the  fun  one  has  puts 
the  mind  in  the  best  condition 
to  get  benefit  from  the  exer- 
cise.    .  Baseball,     tennis, 
and    other    games    of 
this   sort    are    espe- 
cially good. 

There     are 
times     when 


one  cannot 
play,  but 
still  he 
.  needs 


EXERCISE  165 

exercise  just  the  same,  and  then  some  other  kind 
must  be  used.  The  kind  of  exercise  that  makes 
the  muscles  strong  is  the  kind  that  begins  easily 
and  lightly  and  gradually  grows  harder. 

Light  dumb-bells  and  wands  and  light  Indian 
clubs  are  much  better  for  children  than  heavy 
weights  and  large  Indian  clubs  that  tax  the 
strength.  Before  beginning  an  exercise  care 
should  be  taken  to  let  in  plenty  of  pure  air,  be- 
cause the  muscles  cannot  do  their  work  properly 
without  this. 

The  more  the  muscles  act  the  more  food  they 
need,  so  that  we  should  not  choose  for  our  exercise 
a  time  when  we  are  hungry  nor  just  after  a  meal. 
If  we  are  hungry,  the  call  for  so  much  food  for 
the  muscles  makes  a  drain  on  some  other  part  of 
the  body;  and  when  we  have  just  eaten,  the 
stomach  needs  the  blood  to  digest  the  food,  and 
if  it  is  taken  off  by  the  muscles  one  may  suffer 
some  pain  from  indigestion. 

In  playing  and  other  kinds  of  exercise  care 
must  be  taken  to  stop  before  one  is  too  tired. 

People  sometimes  seem  to  think  that  only  boys 
need  exercise,  and  that  girls  will  be  strong  enough 
without,  or  that  girls  do  not  need  to  be  strong. 


166  PHYSIOLOGY 

That  is  a  mistake ;  for  the  muscles  of  a  girl  are 
just  like  the  muscles  of  a  boy,  and  need  to  be  used 
if  they  are  to  be  strong,  and  need  to  be  strong  if 
the  girls  are  to  be  welL 


HOW  TOBACCO  AFFECTS  MUSCULAR 
EXERCISE  AND   GROWTH 

TOBACCO   AND   ATHLETICS 

PROFESSOR  J.  W.  SEAYER  of  Yale  University 
says :  "  Every  schoolboy  knows  that  when  athletes 
are  in  training  for  a  contest  they  are  obliged  to 
abstain  absolutely  from  all  forms  of  tobacco.  Is 
this  done  on  theoretical  or  on  moral  grounds? 
Not  at  alL  It  is  done  because  experience  of 
many  decades  shows  that  when  men  use  tobacco 
they  cannot  do  as  well  as  they  can  when  free 
from  its  effects.  Under  the  influence  of  tobacco 
the  young  man  is  less  alert,  less  steady,  and  has 
less  endurance.  No  man,  when  entering  a  con- 
test, will  knowingly  and  willingly  handicap 
himself. 

"  The  muscle  cells  are  also,  apparently,  only 
slightly  affected  by  it,  but,  the  nerve  supply  to 


TOBACCO  AFFECTS  MUSCULAR  GROWTH   167 

the  muscles  being  affected,  the  power  of  motion 
is  greatly  lessened.  This  has  been  thoroughly 
proven  by  experiments  carried  on  by  Dr.  W.  P. 
Lombard  of  the  University  of  Michigan,  who 
has  shown  that  the  giving  of  even  moderate 
amounts  of  tobacco  in  the  form  of  smoke  lowers 
the  working  power  of  the  human  muscle  by  a 
large  percentage.  His  experiments  were  made 
with  an  instrument  called  the  ergograph,  and  his 
results  may  be  summed  up  as  follows:  In  from 
five  to  ten  minutes  after  beginning  to  smoke  an 
ordinary  cigar,  muscular  power  began  to  dimin- 
ish to  about  25  per  cent  of  its  first  value.  The 
total  work  when  under  the  influence  of  tobacco, 
compared  with  a  similar  normal  period,  was  24.2 
to  44.8. 

"Whenever  it  is  desired  to  secure  the  highest 
possible  working  ability  of  the  body,  as  in 
athletic  contests,  where  the  maximum  of  effort 
is  demanded,  all  narcotic  influences  are  removed 
as  far  as  possible,  tobacco  being  one  of  the  first 
substances  forbidden." 

"All  candidates  for  the  crews  and  other  ath- 
letic sports  of  Yale  College  are  non-smokers." 
—  Medical  News. 


168  PHYSIOLOGY 

DOES    TOBACCO    RETARD   PHYSICAL    GROWTH? 

Professor  Seaver  of  Yale  University  says  that 
"the  records  of  the  students  who  entered  Yale 
in  nine  years,  when  all  of  the  young  men  were 
examined  and  measured,  shows  that  the  smokers 
averaged  fifteen  months  older  than  the  non- 
smokers,  but  that  their  size  —  except  in  weight, 
which  was  from  one  to  three  pounds  more  —  was 
inferior  in  height  to  the  extent  of  nearly  one- 
third  of  an  inch,  and  in  lung  capacity  to  the 
extent  of  over  five  cubic  inches. 

"For  purposes  of  comparison  the  men  com- 
posing a  class  in  Yale  have  been  divided  into 
three  groups.  The  first  is  made  up  of  those 
who  do  not  use  tobacco  in  any  form ;  the  second 
consists  of  those  who  have  used  it  regularly  for 
at  least  a  year  of  the  college  course;  the  third 
group  includes  the  irregular  users.  A  tabulation 
of  the  measurements  of  these  men,  through  a 
period  of  three  and  one-half  years,  shows  that 
the  first  group  grows  in  weight  10.4  per  cent 
more  than  the  second,  and  6.6  per  cent  more 
than  the  third.  In  height  the  first  group  grows 
24  per  cent  more  than  the  second,  and  11  per 


TOBACCO  AFFECTS  MUSCULAR  GROWTH   169 

cent  more  than  the  third;  in  girth  of  chest  the 
first  group  grows  26.7  per  cent  more  than  the 
second,  and  22  per  cent  more  than  the  third; 
in  capacity  of  lungs  the  first  group  gains  77  per 
cent  more  than  the  second,  and  49.5  per  cent 
more  than  the  third." — SEAVER  on  The  Effects  of 
Nicotine. 

These  results  are  essentially  the  same  as  those 
obtained  by  Dr.  E.  R.  Hitchcock  of  Amherst 
College,  who  observed  a  similar  group  of  young 
men  in  a  manner  entirely  independent.  He 
says :  "  In  separating  the  smokers  from  the  non- 
smokers,  it  appears  that  in  the  item  of  weight 
the  non-smokers  have  increased  24  per  cent. 
And  in  lung  capacity  there  is  a  difference  of 
8.36  cubic  inches  (this  is  about  75  per  cent)  in 
favor  of  the  non-smokers,  which  is  3  per  cent  of 
the  total  average  lung  capacity  of  the  class." 

"When  the  Europeans  first  visited  New  Zea- 
land they  found  the  natives  the  most  finely 
developed  and  powerful  men  among  the  islands 
of  the  Pacific.  Since  the  introduction  of  tobacco, 
for  which  these  men  developed  a  passionate  lik- 
ing, they  have,  from  this  source  alone,  become 
decimated  in  numbers,  and  so  reduced  in  stature 


170  PHYSIOLOGY 

and  physical   well-being  as   to  be  an  altogether 

inferior  type  of  men."  —  N.  T.  Medical  Journal. 

"Boys  who  have  used  tobacco  freely  are  thin, 

anaemic,  and  neurotic,  and  are  often  undersized." 

—  GEO.  H.  CATTERMOLE,  M.D.,  Univ.  of  Col. 
"There   is  no  scientific  basis  for  any  supposi- 
tion that  after  sixteen  years  of  age  a  person  can 
use   tobacco    with    impunity.     It   is   bad    at    all 
ages.     The  earlier  the  smoker  begins  the  worse 
for   him,   because   he   has   a   longer  time   in  the 
future  to  injure  himself.     The  nature   of  the  in- 
jury  is  the   s-ame."  —  EDMUND   ANDREWS,  A.M., 
M.D.,  LL.D.,  Professor  of  Surgery,  Northwestern 
University  Medical  School,  Chicago. 

"It  is  positively  harmful  and  detrimental  to 
the  development  of  the  physical  and  mental 
powers  of  our  growing  youth.  Statistics  show 
most  markedly  the  contrast  in  physical  and 
mental  standard  between  the  boy  who  uses 
tobacco  and  the  one  who  does  not."  —  L.  D. 
MASON,  M.D.,  Brooklyn,  NT. 

"I  do  not  hesitate  to  say  that  the  habitual 
use  of  cigarettes  is,  without  question,  a  most 
pernicious  practice,  especially  in  the  immature." 

—  SHELDON  LEAVITT,  M.D.,  Chicago. 


TOBACCO  AFFECTS  MUSCULAR  GROWTH       171 

REASONS   WHY   THE    CIGARETTE   IS    ESPECIALLY 
DANGEROUS 

"Cigarette  smokers  almost  always  inhale  the 
smoke  and  therefore  get  the  harmful  effects  of 
the  tobacco  as  found  in  ordinary  smoking,  and 
in  addition  the  bad  results  obtained  by  drawing 
nicotine  and  the  other  parts  of  the  smoke  into 
the  nasal  passages,  the  pharynx,  larynx,  trachea 
[windpipe],  and  bronchial  tubes.  There  are  good 
authorities  who  maintain  that  the  air  cells  in 
the  upper  part  of  both  lungs  are  affected  by  the 
inhaled  tobacco  smoke. 

"Again,  the  cigarette  is  bad  because  it  is  so 
cheap,  and  consequently  is  within  the  reach  of 
boys  of  tender  age,  who  obtain  them  in  packages 
and  smoke  them  almost  continually  during  the 
waking  hours. 

"  Owing  to  the  sensitiveness  of  the  youthful 
system  to  all  drugs,  this-  results  in  stunted 
growth,  which  leaves  its  imprint  after  the  boy 
has  grown  to  manhood,  and  in  many,  many  cases 
the  effects  are  never  outgrown  even  though  the 
cigarettes  are  discontinued."  -  DR.  CHARLES  H. 
HAMILTON. 


172  PHYSIOLOGY 

"A  good  deal  has  been  said  about  the  evils  of 
cigarette  smoking,  but  not  one  half  the  truth 
has  ever  been  told.  Cigarette  smoking  first 
blunts  the  whole  moral  nature.  It  has  an  ap- 
palling effect  upon  the  physical  system  as  well. 
It  first  stimulates  and  then  stupefies  the  nerves. 
It  sends  boys  into  consumption.  It  gives  them 
enlargement  of  the  heart  and  it  sends  them  to 
the  insane  asylum.  I  am  often  called  in  to  pre- 
scribe for  boys  for  palpitation  of  the  heart.  In 
nine  cases  out  of  ten  this  is  caused  by  the  cigar- 
ette habit.  I  have  seen  bright  boys  turned  into 
dunces,  and  straightforward,  honest  boys  made 
into  miserable  cowards  by  cigarette  smoking. 
That  I  am  speaking  the  truth,  nearly  every 
physician  and  nearly  every  teacher  knows." 
DK.  A.  CLINTON  of  San  Francisco,  Physician  to 
several  boys1  schools. 

The  Superintendent  of  West  Point  says  that 
many  of  the  students  having  developed  eye 
trouble  soon  after  entering  the  academy,  an  ex- 
pert oculist  examined  the  eyes  of  the  students 
and  declared  that  the  weakness  of  vision  was 
caused  by  tobacco  poisoning  from  the  use  of 
cigarettes  before  entering  West  Point. 


CLOTHING  173 

"Tobacco  is  used  by  boys  mostly  in  the  form 
of  cigarettes  —  probably  because  of  their  mild 
taste  and  pleasant  effect.  I  know  one  New 
York  City  boy  who  had  spasmodic  twitchings  of 
the  facial  muscles  as  the  result  of  the  excessive 
use  of  cigarettes.  This  continued  long  after  the 
habit  was  broken/' — GEO.  H.  CATTERMOLE,  M.D., 
University  of  Colorado. 

CLOTHING 

THE  first  thought  in  all  clothing  should  be  its 
usefulness.  '  In  warm  weather  it  should  keep  us 
cool,  in  winter  it  should  keep  us  warm,  and 
all  the  time  it  should  allow  us  to  move  freely, 
to  grow  naturally,  and  to  get  the  best  use  of  our 
organs. 

To  wear  just  what  everybody  else  wears  just 
because  they  wear  it  is  not  enough ;  we  must  do 
some  thinking  for  ourselves. 

If  your  feot  is  wide  across  the  toes,  pointed  shoes 
are  not  meant  for  you,  even  if  other  people  do  wear 
them.  A  shoe  should  fit  the  foot.  If  it  is  so 
large  that  it  slips  about,  or  so  small  that  it 
pinches,  it  will  cause  corns.  The  soles  should  be 


174  PHYSIOLOGY 

thick  enough  to  keep  the  feet  dry,  and  to  keep  one 
from  feeling  every  little  uneven  and  rough  place 
he  steps  upon.  One  can  stand  and  walk  much 
longer  without  being  tired  if  he  wears  shoes  with 
thick  soles  and  broad  low  heels  than  he  can  if  he 
wears  shoes  with  thin  soles  and  high  heels. 

The  clothing  should  not  be  heavy,  and  the 
weight  should  hang  from  the  shoulders.  Tight 
bands  around  the  waist  throw  all  the  weight  upon 
the  soft  parts  of  the  body  instead  of  upon  the 
bones. 

Tight  clothing  presses  upon  the  young  bones 
and  gets  them  out  of  shape.  If  the  ribs  are 
pressed  in,  the  lungs  and  liver  do  not  have  room 
enough  to  do  their  work  well  (see  Fig.  34). 

The  clothes  which  one  wears  during  the  day 
take  up  the  perspiration  which  the  body  throws 
off,  and  they  should  be  aired  at  night  while  some- 
thing else  is  worn. 

One  should  not  wear  too  much  clothing,  as  it 
causes  the  body  to  perspire  and  makes  the  cloth- 
ing wet ;  then  when  one  goes  to  a  cooler  place  and 
the  air  strikes  one  he  is  likely  to  take  cold. 

When  exercising  the  air  comes  into  the  body 
faster  and  the  heart  beats  faster  than  when  one 


CLOTHING 


175 


rests.  The  clothing  over  these  organs  of  breath- 
ing and  circulation  should  then  be  very  loose  to 
allow  them  to  work  freely,  and  as  the  body  must 
take  many  positions,  the  clothing  should  be  light 
and  should  be  cut 
in  such  a  way  as 
to  allow  the  limbs 
plenty  of  freedom. 
Tight  bands  or 
collars  worn  around 
the  neck  keep  the 
blood  from  flowing 
freely  to  and  from 
the  head,  and  are 
likely  to  cause  head- 
ache, and  one  can- 
not do  clear  think- 

•-i/u   U       J      i.          Caused  by  wearing   clothing  tight  at  the 
ing  With  neaaactie.         waist.    For  the  natural  position  of   the 

Of  course,  clothes     ribs  see  Fig*  22' 
should  be  neat  and  clean,  but  those  that  cost  the 
most  are  not  always  the  ones  that  look  the  best 
or  give  the  most  comfort. 

To  be  well  dressed,  a  child  should  be  dressed 
to  suit  his  work  or  play,  in  clothing  which  is 
loose  enough  to  allow  him  to  get  the  most  fun 


FIG.  34.  —  DEFORMITY  OF  THE  RIBS. 


176  PHYSIOLOGY 

out   of    his   play   and    the    most   good   from   his 
study. 

One  should  always  wear  enough  clothing  to 
keep  from  feeling  cold.  No  part  of  the  body  can 
do  its  work  so  well  when  cold.  We  are  less  able 
to  withstand  causes  of  sickness  when  we  are 
chilled.  Whenever  we  go  from  a  warm  room  into 
cold  air  we  should  have  an  extra  wrap  to  throw 
on.  If  the  weather  suddenly  turns  cold  when  we 
are  unprepared  for  it,  we  can  resist  the  cold  for 
a  time  by  vigorous  exercise  until  we  can  reach  a 
warm  room  or  procure  warm  wraps. 

HOW    LACK    OF    CLEANLINESS    LEADS     TO 
DISEASE 

IF  we  study  the  habits  of  animals,  we  learn 
that  many  of  them  give  special  attention  to  per- 
sonal cleanliness.  The  bird  takes  his  morning 
shower  bath  in  the  clear  stream,  and,  after  his 
breakfast  of  strawberry  or  caterpillar,  he  wipes 
off  his  bill  as  carefully  as  all  boys  and  girls 
should  brush  their  teeth  after  eating.  The  duck 
takes  her  swim  and  then  spends  a  long  time  oil- 
ing and  arranging  her  feathers.  The  hen  prefers 


LACK  OF  CLEANLINESS  LEADS  TO   DISEASE     177 

a  dry  bath  and  dusts  her  feathers  with  dry  earth. 
Pussy  washes  her  coat  with  her  rough  tongue. 
The  horse  gives  his  coat  a  thorough  rubbing  down 
by  rolling  on  the  ground  and  finishes  with  a  vig- 
orous shake.  Even  the  pig,  it  is  said,  would  keep 
clean  if  given  clean  water  and  a  clean  pen. 

The  bees  and  the  birds  could  also  give  some 
people  lessons  in  neat  housekeeping.  They 
quickly  remove  all  foul  matter  that  would  bring 
sickness  into  their  dwellings,  while  around  human 
habitations,  garbage  and  decaying  matter  are 
sometimes  allowed  to  -lie  and  poison  the  air. 

It  has  recently  been  found  that  flies  and  mos- 
quitoes and  other  insects  are  carriers  of  the  germs 
of  typhoid  fever,  malaria,  and  other  diseases. 
If  we  do  not  keep  our  doors  and  windows 
screened  in  summer,  flies  will  come  from  unclean 
places  outside  into  our  rooms,  and  go  directly 
into  our  sugar  bowls  and  cream  pitchers. 

The  mosquito  comes  from  his  cradle  in  the 
slimy  bog  and  thrusts  germs  of  malaria  into  our 
veins  as  he  lances  them  with  his  bill  to  draw  blood 
for  his  supper.  Screens  for  our  windows  and 
doors  are  therefore  necessary  to  save  us  doctors' 
bills. 

HALL'S  INT.  PHYS. — 12 


178  PHYSIOLOGY 

In  some  countries  fleas  and  rats  have  been 
found  to  spread  the  germs  of  a  dreadful  disease 
called  the  plague.  Some  of  our  common  insects, 
it  is  thought,  may  also  spread  germs  of  disease. 
We  must  therefore  keep  our  houses  free  from 
vermin  and  insects,  which  we  can  do  by  traps, 
sulphur  fumes,  and  other  means. 

Carpets  and  woolen  hangings  that  collect  dust 
and  attract  moths  are  not  so  healthful  as  smooth 
floors  that  can  be  quickly  dusted  every  day  and 
dainty  muslin  curtains  that  can  be  easily  washed 
when  soiled. 

The  sunlight  is  a  great  purifier,  and  when  we 
have  made  our  clothes,  our  persons,  and  our  houses 
as  clean  as  soap  and  water  and  labor  can  make 
them,  the  sunshine  will  still  further  aid  us  in 
driving  out  the  lurking  germs  of  disease. 


INDEX 


Adam's  apple,  76. 

Air  cells  or  sacs,  76. 

Air,  need  of  pure,  78. 

Alcohol,  57. 

Alcohol  a  narcotic,  137. 

Alcohol  and  bathing,  99. 

Alcohol  and  the  muscles,  161. 

Alcohol  and  the  skin,  89. 

Alcohol,  effect  of,  on  the  lungs,  82. 

Artery,  70. 

Back-boned  animals,  153. 

Bananas,  25. 

Bathing,  93. 

Bathing  and  alcohol,  99. 

Blood,  52,  53,  63. 

Blood,  circulation,  68. 

Blood,  how  carried  over  body,  66. 

Blood,  how  made  pure,  74. 

Body,  how  it  moves,  156. 

Body,  how  warmed,  99. 

Brain,  126. 

Bronchial  tubes,  76. 

Bronchioles,  76. 

Cabbages,  20. 
Capillaries,  70. 
Carbon  dioxide,  78. 
Care  of  lungs,  79. 
Care  of  muscles,  159. 
Care  of  stomach,  46. 
Care  of  teeth,  42. 
Cereals,  grinding,  18. 
Cerebellum,  128. 
Cerebrum,  128. 
Chestnuts,  26. 
Cider,  57. 
Cigarette,  171. 
Cleanliness  and  health,  97. 
Clothing,  173. 
Clothing  and  deformity,  175. 


Cocoanuta,  25. 
Coffee,  25. 

Dates,  25. 

Digestive  tube,  46. 

Disease  and  uncleanness,  176. 

Drinks,  33. 

Duodenum,  45. 

Ear,  diagram  of,  110. 

Eat,  what  we,  16. 

Eat,  why  we,  14. 

Education,  129-131. 

Eggs,  24. 

Eggs  and  milk,  17. 

Enemies  of  body,  136. 

Epiglottis,  43,  44,  76. 

Esophagus,  44,  45. 

Exercise,  163. 

Eye,  105. 

Eye,  a  section  of,  104. 

Eyebrow,  105. 

Eye,  iris,  105. 

Eyelids,  105. 

Eye,  pupil,  105. 

Eyes,  "sore  eyes,"  107. 

Fat,  20. 

Figs,  25. 

Fish,  catching,  23. 

Food,  fruit,  19. 

Food,  how  digested,  44. 

Food,  how  swallowed,  43. 

Food,  how  to  prepare,  26. 

Food,  how  taken  up  from  intestine. 

46. 

Food,  how  taken  up  by  body,  49. 
Food,  how  used  by  body,  53. 
Food,  meat,  19. 
Food,  nature's,  17. 
Food,  vegetables,  19. 
179 


180 


INDEX 


Food,  where  does  it  come  from  ?  21. 

Foods,  16. 

Foods,  cereal,  18. 

Fruit,  19. 

Fruit  juice,  when  harmful,  55. 

Gall  bladder,  45. 
Games,  130. 
Gastric  juice,  45. 
"  Goose  flesh,"  93. 

Hair  and  nails,  90. 
Hair  tube  of  skin,  88. 
Health  and  cleanliness,  97. 
Hearing,  109. 
Heart  beat  and  pulse,  71. 
Heart,  diagram,  67. 
Heart,  picture,  66. 

Intestine,  45,  50. 
Iris  of  eye,  105. 

Lacteals,  52. 

Larynx,  76. 

Lashes  of  eye,  105. 

Lemons,  24. 

Lids  of  eyes,  105. 

Lungs,  76. 

Lungs,  care  of,  79. 

Lungs,  effect  of  alcohol  on,  82. 

Meat,  19. 

Milk,  24. 

Milk  and  eggs,  17. 

Mouth,  its  work,  40. 

Muscle  of  arm,  158. 

Muscles,  care  of,  159. 

Nails  and  hair,  90. 
Narcotics,  137. 
Narcotics  and  the  heart,  72. 
Nerves  of  motion,  126. 
Nerves  of  sense,  126. 

Oil  gland  of  skin,  88. 
Opium,  62. 
Oranges,  24. 
Organ  of  smell,  116. 


Organs  with  which  we  breathe,  75. 
Oxygen,  78. 

Papillae  of  tongue,  118. 
Pharynx,  44. 
Pineapples,  25. 
Playing,  130. 
Poison,  57. 
Potatoes,  20. 
Prunes,  25.     ' 
Pulse,  71. 
Pupil  of  eye,  105. 

Raisins,  25. 
Rice,  24. 
Root  beer,  61. 

Salt  works,  24. 

Seeing,  103. 

Sheep,  25. 

Skeleton,  153. 

Skin,  86,  88. 

Skin,  effect  of  alcohol  on,  89. 

Sleep,  133. 

Smell,  115. 

Soft  palate,  43. 

Spinal  cord,  126. 

Starch,  20. 

Stomach,  45. 

Stomach,  care  of,  46. 

Strawberries,  42. 

Sugar,  20. 

Sugar  cane,  23. 

Sweat  gland  of  skin,  88. 

Sweat  tube  of  skin,  88. 

Table  manners,  28-31. 

Taste,  117, 118. 

Tea,  25. 

Teeth,  care  of,  42. 

Think,  how  we,  127. 

Thoracic  duct,  52. 

Tobacco,  61. 

Tobacco  a  narcotic,  137. 

Tobacco  and  athletics,  166. 

Tobacco  and  the  muscles,  162. 

Tobacco  and  growth,  168. 


INDEX 


181 


Tobacco,  what  doctors  and  teachers 

say  of  it,  141. 
Tongue,  118. 
Touch,  120, 121. 
Trachea,  76. 

Uvula,  43,  44. 

Vegetables,  19. 
Vein,  70. 
Ventilation,  80, 


Vermiform  appendix,  45. 
Villas  of  intestine,  51. 

Waste  matter  of  body,  84. 
Water,  pure,  35. 
Water,  rain,  34. 
Wheat,  reaping,  22. 
Windpipe,  44,  76. 
Wine,  57. 

Yeast  plant,  57. 


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By  FREDERIC  H.  RIPLEY  and  THOMAS  TAPPER 


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3»  Just  enough  physiography  is  included  to  develop  the  funda- 
mental relations  of  geography  and  to  animate  and  freshen  the  study 
without  overloading  it  in  this  direction. 

4.  The  simplicity  of  the  older  methods  of  teaching  this  subject  is 
combined  with  just  so  much  of  the  modern  scientific  methods  of  pres- 
entation as  is  thoroughly  adapted  to  elementary  grades. 

5.  The  physical  maps  of  the  grand  divisions  are  drawn  to  the  same 
scale,  thus  enabling  the  pupils  to  form  correct  concepts  of  the  relative 
size  of  countries. 

6.  The  political   and  more  detailed  maps  are  not  mere  skeletons, 
giving  only  the   names  which    are   required  by  the  text,  but  are  full 
enough  to  serve  all  ordinary  purposes  for  reference.     In  addition,  they 
show  the  principal  railroads   and  canals,  the  head  of  navigation  on  all 
important  rivers,  and  the  standard  divisions  of  time. 

7.  The  illustrations    are  new  and  fresh,  reproduced  mostly  from 
photographs  collected  from  all  parts  of  the  world  with  a  view  to  helping 
out  and  explaining  the  text  and  not  for  mere  embellishment. 

8.  To  secure  proper  practice  in  map  reading,  formal  map  studies 
or  questions  have  been  inserted  with  each  map,  directing  attention  to 
the  most  important  and  essential  features. 


Correspondence    regarding    the    examination    and    introduction    of 
Roddy's  Geographies  is  cordially  invited  and  itnll  receive  prompt  attention. 

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BARNES'S  NEW  HISTORIES 
OF  THE   UNITED  STATES 


BARNES'S  ELEMENTARY  HISTORY  OF  THE  UNITED  STATES 

Told  in  Biographies  by  JAMES  BALDWIN.     Cloth,   I2mo, 

360  pages.     With  maps  and  illustrations    ....     $0.60 

BARNES'S  SCHOOL  HISTORY  OF  THE  UNITED  STATES 

Thoroughly   revised   and    brought   down   to    date.       Half 
leather,  8vo,  432  pages.     With  maps  and  illustrations         .        1.00 


THESE  standard  and  popular  histories  have  been  thoroughly 
modernized,  both  as  to  appearance  and  contents.  They 
offer  present-day  views  of  history  and  methods  of  teaching. 
The  larger  book  has  been  revised  in  every  particular,  and  the 
smaller  one  entirely  rewritten  by  that  charming  and  well-known 
writer  for  children,  DR.  JAMES  BALDWIN. 

The  Elementary  History  tells  the  story  of  the  country 
in  a  series  of  biographies  of  important  men  as  recommended 
by  the  Committee  of  Fifteen.  The  incidents  narrated  show 
the  manners  of  the  time,  and  the  stories  are  all  intensely  inter- 
esting. The  numerous  illustrations  form  an  important  aid  to 
the  understanding  of  the  text. 

In  the  School  History,  while  the  fascinating  literary  style 
and  the  remarkably  successful  distinctive  features  of  the  original 
volume  have  been  retained,  greater  prominence  has  been  given 
to  industrial  and  social  development.  References  for  collat- 
eral reading  have  been  inserted  at  frequent  intervals,  and  many 
new  maps  and  pictures  introduced. 

Write  for  illustrated  descriptive  circular. 


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Barnes's  Natural  Slant  Penmanship 


The  system  of  writing  represented  in  these  new  copy 
books  combines  all  the  advantages  of  the  vertical  with  the 
speed  and  beauty  of  regular  slant  writing. 

It  is  well  known  that  an  extreme  slant  tends  to  angu- 
larity, while  vertical  writing  is  usually  slow  and  tends  to 
an  unsightly  back-hand  or  irregular  slant.  If  left  to 
themselves,  without  specific  directions,  children  naturally 
fall  into  a  certain  slant  in  writing, — intermediate  between 
vertical  and  slant  writing.  This  natural  slant  has  been 
adopted  as  the  standard  in  these  copy  books. 

FORMS  OF  LETTERS. — Natural  Slant  copies  are  de- 
signed to  be  written^  not  printed.  They  have  the  simplicity 
and  the  full,  round,  open  style  of  the  best  vertical  forms, 
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have  characterized  that  style  of  writing.  In  every  instance 
the  form  of  capital  employed  has  been  selected,  first, 
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execution;  and  third,  because  of  its  graceful  form.  Every 
copy  is  sensible  and  significant ',  and  as  nearly  as  possible  the 
subject  matter  relates  to  topics  which  interest  the  pupils 
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In  other  words,  the  writing  exercises  are  made  to  correlate 
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THE  SERIES  includes  Books  A,  B,  C,  and  D,  small  size, 
illustrated,  to  be  written  with  pen  or  pencil,  and  Books  i  to  8, 
full  size,  the  first  two  books  illustrated.  A  set  of  penman- 
ship WALL  CHARTS  in  four  sheets  is  published  to  accom- 
pany this  series  of  copy  books. 

BOOKS  A,  B,  C,  and  D,  per  dozen $0.60 

BOOKS  1  to  8,  per  dozen 75 

CHARTS,  per  set  of  four  sheets 1.50 


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Baird's  Graded  Work  in  Arithmetic 

By  S.  W.  BAIRD 

Principal  Franklin  Grammar  School,  Wilkesbarre,  Pa. 


First  Year    -    -    - 

Boards,  $0.  1  8 

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BAIRD'S  Graded  Work  in  Arithmetic  consists  of 
eight  books  designed  for  use  in  all  the  grades  of 
elementary  schools  where  the  subject  is  taught. 
The  series  furnishes  to  pupils  text-books  carefully 
planned  to  strengthen  their  powers  of  mathematical 
reasoning,  at  the  same  time  presenting  a  range  of  topics 
sufficiently  comprehensive  to  familiarize  them  with  the 
important  practical  applications  of  the  science  to  the 
wants  of  common  life.  The  Practical  Arithmetic  is 
designed  for  general  use  in  grammar  grades  and,  with 
the  first  four  books,  forms  a  five-book  series. 

The  books  represent  the  latest  and  best  methods  of 
teaching  arithmetic.  They  abound  in  combinations  of 
oral  and  written  work,  and  in  copious  examples  for 
drills  and  reviews.  Each  subject  is  treated  both  peda- 
gogically  and  mathematically.  Common  sense  and  the 
keen  logic  of  the  mathematician  are  shown  on  every 
page.  Each  book  begins  with  a  review  of  the  essential 
principles  studied  in  the  previous  book.  The  subjects 
are  taken  up  alternately,  in  accordance  with  the  ability 
of  the  child,  not  as  complete  wholes,  in  this  way  follow- 
ing the  so-called  "spiral  system." 

Great  care  has  been  taken  in  the  selection  of  illus- 
trative examples  and  operations.  Explanations  and 
analyses  have  been  given  in  full,  in  order  that  the  prin- 
ciples involved  may  be  easily  and  clearly  understood 
by  the  pupil  with  but  little  assistance  from  the  teacher. 

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Baldwin's  School  Readers 

By  JAMES  BALDWIN 

Editor  of  "  Harper's  Readers,"  Author  of  "Old  Greek  Stories,"  "Old 
Stories  of  the  East,"  etc. 


In  method  and  in  subject  matter,  as  well  as  in  artistic 
and  mechanical  execution,  these  new  readers  establish  an 
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for  the  purpose  of  ornament,  but  are  intended  to  assist 
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BALDWIN'S  SCHOOL  READERS— EIGHT  BOOK  EDITION 

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Combined  Sixth  and  Seventh  Years.    480  pages   .         .  65  cents 


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on  receipt  of  the  price. 

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ELEMENTARY    NATURE   STUDY 

Abbott's  A  Boy  on  a  Farm     .        .        .        .45  cents 

Two  stories  by  Jacob  Abbott,  revised,  and  in  new  and  attractive  form. 
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The  object  of  these  stories  is  to  arouse  the  interest  of  children  in  certain 
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Bradish's  Stories  of  Country  Life     .         ...     40  cents 

These  recollections  of  a  childhood  spent  on  a  northwestern  farm  aim 
to  emphasize  the  attractiveness  of  life  in  the  country,  and  to  add  to 
its  charm  by  awakening  an  intelligent  interest  in  its  many  activities. 

Dana's  Plants  and  Their  Children   .         .        .65  cents 

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